1. Introduction

The BAS Remote Master provides the ultimate in flexibility. It can be used for expansion I/O at remote locations where an Ethernet connection exists. Its built-in router and gateway capability addresses unique integration needs where more than one communications protocol is involved. It can function as a controller with its resident Sedona Virtual Machine. Powered by a Linux engine, the BAS Remote Master can operate as BACnet/IP or Modbus TCP remote I/O, Sedona controller, Modbus Serial to Modbus TCP router, Modbus Serial to BACnet gateway, and Modbus master to attached Modbus slaves – all at the same time. A 10/100 Mbps Ethernet port allows connection to IP networks and popular building automation protocols such as Modbus TCP, BACnet/IP, and Sedona SOX. Six universal I/O points and two relay outputs can be configured through resident web pages using a standard web browser and without the need of a special programming tool. A 2-wire Modbus serial port can greatly expand the I/O count with built-in routing to Modbus TCP clients. If BACnet mapping is preferred, the unit incorporates a Modbus serial to BACnet/IP gateway. Additional universal I/O can be achieved with the simple addition of BAS Remote Expansion modules. The BAS Remote Master PoE has the same capabilities as the BAS Remote Master except it is powered over the Ethernet connection — thereby providing a “One Cable Solution”.

Both the BAS Remote Master and BAS Remote Expansion modules have the same I/O capability. Six universal input/output points are provided on each module. Depending upon configuration, each unit can accommodate a contact closure from a digital point, a thermistor, voltage or current analog input from a field transmitter or supervisory controller. Analog inputs can range from 0–5 VDC, 0–10 VDC or 0–20 mA. Inputs can be scaled to accommodate ranges such as 1–5 VDC, 2–10 VDC, and 4–20 mA. Input point resolution is 10-bits.

Type II and III 10k Ohm thermistor calibration curves are resident in the BAS Remote. Single-point calibration of temperature is accomplished using the internal web server. Inputs can accept pulse trains in the range of 0–40 Hz (50% duty cycle) to measure flow rates.

Analog outputs can be 0–10 VDC or 0–20 mA. However, scaling for 2–10 V, 0–5 V, 1–5 V and 4–20 mA is possible. LED indicators identify the state of I/O points. Output point resolution is 12 bits.

There are two relay outputs available with both normally open (NO) and normally closed (NC) contacts. The relay output rating is 30 VAC/VDC, 2A.

There are two non-isolated 2-wire EIA-485 expansion ports on the master module. The downstream port (DN) is intended for expansion modules while the Modbus (MB) port functions as either a Modbus TCP router or Modbus serial to BACnet gateway — allowing for the attachment of Modbus 2-wire or 3-wire EIA-485 serial devices. On BAS Remote Expansion modules, the two ports are marked UP and DN, and are dedicated for communication with the BAS Remote Master module and other expansion modules.

All field connectors are removable — making field replacement of units quick and simple.

A single RJ-45 shielded connector provides the 10/100 Mbps twisted-pair Ethernet connection. The unit supports auto-negotiation of data rate and duplex. A resident web server facilitates commissioning and troubleshooting. Configuration is accomplished via Ethernet. Java must be enabled in the browser used to access the BAS Remote.

Power for the BAS Remote can be derived from a 24 VAC Class 2 transformer capable of delivering 17 VA or from a 24 VDC power supply capable of at least 10 W. Since the unit incorporates a half-wave rectified power supply, attached I/O points and the power supply can share a common ground. Therefore, the BAS Remote can be powered by the same control transformer used to power other half-wave rectified control equipment. The BAS Remote can be DIN-rail mounted into a control panel. If panel mounting is required, use the supplied mounting tabs.

The BAS Remote conforms to the BACnet/IP standard and therefore allows field I/O to be directly accessed via Ethernet without the need of a router. A standard web browser with Java enabled is used for commissioning and troubleshooting. The BAS Remote adheres to the BACnet Application Specific Controller (B-ASC) profile.


2. System Configuration

Four tabs exist on the configuration screen.

2.1 System

System NameGive your system any name you wish.
IP AddressChanging the default value of 192.168.92.68 is recommended.
Subnet MaskThe default value of 255.255.255.0 is adequate for most users.
Gateway AddressIf your Ethernet LAN has a gateway (router) enter its address here.
Main Unit NameGive your Master module any name you wish.
Expansion UnitsChoose from the default of 0 to as many as 3 units. This value will set the number of tabs that you see atop the main screen.

NOTE:Whether you are configuring System, BACnet, Modbus or Virtual values, clicking “UPDATE” will save your values to internal memory, but you must reboot the Master module by cycling power before the new values will apply!

2.2 BACnet

Device InstanceThis is a 22-bit value (0–4,194,303). Each BACnet network device must have a unique device instance. The default value is 2749.
UDP PortThe default value of 0xBAC0 should usually not be changed.
BBMD IP AddressEnter the address of the BBMD with which the BAS Remote will perform Foreign Device Registration (FDR) if the BBMD is not located on the same subnet as the BAS Remote.
BBMD Reg TimeEnter the interval (in seconds) between successive foreign device registrations.

2.3 Modbus

Modbus configuration is only required if Modbus serial devices are attached to the MB bus. Communication settings between the Master module and the Expansion modules are preset and cannot be changed.

Modbus AddressAddress 1 is pre-assigned to the Master module while Expansion modules are assigned addresses 2, 3 and 4 assuming Expansion units exist. The actual Expansion address depends upon the order of cabling to the Master. In addition to address 1, the Master module is also pre-assigned addresses 8 and 9 for internal functions. It is best to assume that addresses 1 through 9 are reserved for BAS Remote equipment so assign addresses from 10 to 247 to attached Modbus devices.
BaudrateAll Modbus devices attached to the MB bus must have the same baud rate. Baud rates range from 2,400 to 115,200. The default is 19,200.
ProtocolAll Modbus devices attached to the MB bus must use the same protocol. The choices are RTU and ASCII. The default is RTU.
ParityAll Modus devices attached to the MB bus must use the same parity. The choices are NONE, ODD or EVEN. The default is EVEN.
Command TimeoutSet how long the Master will wait for a slave to respond. The range is 50–3000 ms with a default of 1,000. If a device fails to respond, it is placed into an offline queue. Devices in this queue are checked every offline poll period.
Inter Scan DelaySet the desired delay between each poll cycle from 100-30,000 ms. The default is 2,000.
Offline Poll PeriodSet how often the Master will check to see if a slave device is back online. The range is 2,000-30,000 ms. The default is 15,000.
Consecutive Read DelaySets the delay between back-to-back accesses of the same slave device. The range is 0-100 ms and the default is 0.
Inter-Character GapThis maximum (1.5 character times) is what Modbus allows between characters. If a device exceeds the allowable time, set this to the highest possible value for the device. The default of 0 is recommended, but settings between 0 and 10 ms are possible.

2.4 Virtual

The BAS Remote can store data independent of I/O Channel values. These stored values are called Virtual Points because they are not required to be related to physical I/O points. These virtual points can be treated as Modbus registers, BACnet objects or Sedona Framework components.

InstanceThis read-only number is created from the BACnet Type. It is of the form 8xyyyy, where the x defaults to 4 (register) but after the Apply Object Changes button is clicked it will become 0 if the Type is Binary Output or 1 if the Type is Binary Input. The value of yyyy is automatically incremented as objects are added to the list of Virtual Points in the left side of Figure 20. This virtual object can be written or read via its Modbus/TCP address. Its address will be 8 and the register number will be YYYY. The binary input/output can be written/read via 0YYY or 1YYY.
NameGive the Virtual Point any name you wish. This will be the BACnet object name for this virtual object.
BACnet DescriptionGive the BACnet channel any description you wish.
BACnet TypeSelect the Type from the drop-down menu.Below, check the “Retentive” box to preserve counts despite a power failure. “Float” indicates how this virtual object will be accessed via Modbus/TCP. If checked, this object will be accessed as a 32-bit float value. If unchecked, it will be accessed as a 16-bit register. NOTE: Analog Value, Analog Input and Binary Input types will not be writeable via BACnet. Analog output and Binary Input can be written via BACnet.
BACnet Unit GroupSelect the Unit Group from the drop-down menu.
BACnet Unit ValueSelect the Unit Value from the drop-down menu.
BACnet COV IncrementOnce the channel value changes by this amount (up or down), a COV message is sent to subscribers.


3. Web Server Screen Overview

From the Web Server Screen, you can configure all I/O channels, view their status or force them as part of a commissioning process. The Configure Settings button (just below the device image) provides access to the basic device configuration fields.

The BAS Remote image includes a graphic representation of each I/O Channel. Each of the 8 channels has two icons ( and ) that open additional windows used for configuring or forcing each Channel.

Other buttons located beneath and to the right of the device image are:
MapThis accesses the Modbus Mapping function.
Modbus UtilityThis accesses the Modbus Utility function.
Set TimeThis function is used with Sedona Framework. The time can also be set by the Time Synchronization BIBB.

The large grey section at the bottom of the screen labelled Current Settings is the device “Monitor” — a read-only display of information for the BAS Remote module currently selected. The tab in bold face near the top of the screen indicates the module selected.

In the upper-left portion of the Monitor, two values (Unit Name and Modbus Address) are displayed for the currently selected module.

To the right of the Modbus Address value is a box which reports one of two possible pieces of information — depending on the type of BAS Remote module currently selected. When the master is selected, the box will display the BACnet Device Instance of the master. If an expansion module is selected, the box will report the module’s status: It will be ONLINE if its connection to the master is valid or OFFLINE if the connection is invalid. An OFFLINE report usually means the expansion module cannot communicate with the master due to a cabling issue.

In the upper-right portion of the Monitor, the status of each channel (point) is reported with the Override indicators and the LED Status indicators. All of these LEDs are refreshed at the rate of once per second.

The lower portion of the Monitor displays the Channel Names and their Present Values.

3.1 Channel Configuring

To configure a channel, view the Web Server Page, click on the icon for the channel of interest and make adjustments in the new screen that appears. Your selected channel is confirmed by the large number on the left side of the new screen. Clicking on the Save button is confirmed by the button briefly changing from light blue to dark blue. If you attempt to set an illegal value, the button will not change colour.

3.1.1 Analog Input Configuring

You can define any channel 1–6 as type “INPUT: 0–10V Analog” or “INPUT: 0–5V Analog”. Such a channel can accept an input voltage in the range of 0–10 volts or 0–5 volts. On this screen, you can adjust any of the following parameters.

Channel NameYou can name the channel using no more than 63 characters.
BACnet Unit GroupThe Electrical default can be set to any option in the list.
BACnet Unit ValueThe VOLTS default can be set to any option in the list. The available options depend on the BACnet Unit Group you specify.
BACnet COV Increment Once the channel value changes by this amount (up or down), a COV message is sent to subscribers.
BACnet DescriptionYou can enter any string using no more than 63 characters.
ACTUAL HIGHThis specifies the highest value within the range.
ACTUAL LOWThis specifies the lowest value within the range.
SCALED HIGHYou can set a physical value corresponding to the high value.
SCALED LOWYou can set a physical value corresponding to the low value.

3.1.2 Analog Output Configuring

You can define any channel 1–6 as type “OUTPUT: 0–10V Analog”. Such a channel can supply an output voltage in the range of 0–10 V. On this screen, you can adjust any of the following parameters.

Channel NameYou can name the channel using no more than 63 characters.
BACnet Unit GroupThe Electrical default can be set to any option in the list.
BACnet Unit ValueThe VOLTS default can be set to any option in the list. The available options depend on the BACnet Unit Group you specify.
BACnet COV Increment Once the channel value changes by this amount (up or down), a COV message is sent to subscribers.
BACnet DescriptionYou can enter any string using no more than 63 characters.
ACTUAL HIGHThis specifies the highest value within the range.
ACTUAL LOWThis specifies the lowest value within the range.
SCALED HIGHYou can set a physical value corresponding to the high value.
SCALED LOWYou can set a physical value corresponding to the low value.
Initial Value (Scaled)The Off default outputs 0, but you can preset a Scaled value.

3.1.3 Binary Input Configuring

You can define any channel 1–6 as type “INPUT: Binary”. On this screen, you can adjust the following parameters.

Channel NameYou can name the channel using no more than 63 characters.
BACnet Unit GroupThe Others default can be set to any option in the list.
BACnet Unit ValueThe NO_UNITS default can be set to any option in the list. The available options depend on the BACnet Unit Group you specify.
BACnet DescriptionYou can enter any string using no more than 63 characters.

3.1.4 Current Input Configuring

You can define any channel 1–6 as type “INPUT: 0–20mA”. Such a channel can accept an input current in the range of 0–20 mA. On this screen, you can adjust any of the following parameters.

Channel NameYou can name the channel using no more than 63 characters.
BACnet Unit GroupThe Electrical default can be set to any option in the list.
BACnet Unit ValueThe MILLIAMPERES default can be set to any option in the list. The available options depend on the BACnet Unit Group you specify.
BACnet COV Increment Once the channel value changes by this amount (up or down), a COV message is sent to subscribers.
BACnet DescriptionYou can enter any string using no more than 63 characters.
ACTUAL HIGHThis specifies the highest value within the range.
ACTUAL LOWThis specifies the lowest value within the range.
SCALED HIGHYou can set a physical value corresponding to the high value.
SCALED LOWYou can set a physical value corresponding to the low value.

3.1.5 Thermistor Input Configuring

You can define any channel 1–6 as a Type II or III thermistor input. On this screen, you can adjust any of the following parameters.

Channel TypeYou can select a Type II or Type III thermistor profile.
Channel NameYou can name the channel using no more than 63 characters.
BACnet Unit GroupThe Temperature default can be set to any option in the list.
BACnet Unit ValueThe DEGREES_FAHRENHEIT default can be set to any option in the list. The available options depend on the BACnet Unit Group you specify.
BACnet COV Increment Once the channel value changes by this amount (up or down), a COV message is sent to subscribers.
BACnet DescriptionYou can enter any string using no more than 63 characters.
OffsetYou can specify a (+) or (–) number of degrees offset — if, for example, the thermistor in use is known to be delivering an inaccurate reading. Either type of thermistor can normally measure from –35º and +120º Fahrenheit.
Temp UnitsThe Fahrenheit default scale can be changed to Celsius.

3.1.6 Pulse Input Configuring

You can define any channel 1–6 as type “INPUT: Pulse”. Such a channel can accept a pulse train in the range of 0–40 Hz. The channel BACnet type will be Analog Value.

NOTE: The value reported by this channel via BACnet will be a 32-bit float as this is an Analog Value. To provide accurate values when counting input pulses, this value will rollover at 224-1.

To reset the pulse input value, you can (via BACnet) take the channel out of service and write a desired value — such as 0 — and then put the channel back in service to allow pulse counting to continue. This value can also be reset by writing a new value to it via the map web page or via Modbus/TCP or via webservices or via a custom webpage which can write to the instance associated with this channel.

On this screen, you can adjust any of the following parameters.

Channel NameYou can rename the channel using no more than 63 characters.
BACnet Unit GroupThe Others default can be set to any option in the list.
BACnet Unit ValueThe NO_UNITS default can be set to any option in the list. The available options depend on the BACnet Unit Group you specify.
BACnet COV Increment Once the channel value changes by this amount (up or down), a COV message is sent to subscribers.
BACnet DescriptionYou can enter any string using no more than 63 characters.
ACTUAL HIGHThis specifies the highest value within the range.
ACTUAL LOWThis specifies the lowest value within the range.
SCALED HIGHYou can set a physical value corresponding to the high value.
SCALED LOWYou can set a physical value corresponding to the low value.
PeriodIf the “Rate” option has been selected, this specifies the period in seconds — otherwise, this field is not present on the screen.
RateThis specifies that the rate of the input is being obtained.
AccumulateThis specifies that the input pulses are being accumulated (absolute count) — with no limit to the time during which pulses are counted.
High Level(V)You can specify a value from 10 down to (but more than) the "Low Level".
Low Level (V)You can specify a value from 0 up to (but less than) the "High Level".

3.1.7 Relay Output Configuring

Channels 7 and 8 are fixed as type “OUTPUT: Relay”. Each channel provides a relay contact rated at 30 VAC/DC, 2A. Each relay has a normally-open and a normally-closed set of contacts. On this screen, you can adjust one parameter.

Channel NameYou can name the channel using no more than 63 characters.
BACnet Unit GroupThe Others default can be set to any option in the list.
BACnet Unit ValueThe NO_UNITS default can be set to any option in the list. The available options depend on the BACnet Unit Group you specify.
BACnet COV Increment Once the channel value changes by this amount (up or down), a COV message is sent to subscribers.
BACnet DescriptionYou can enter any string using no more than 63 characters.
ACTUAL HIGHThe default value of 1 is unchangeable.
ACTUAL LOWThe default value of 0 is unchangeable.
SCALED HIGHThe default value of 1 is unchangeable.
SCALED LOWThe default value of 0 is unchangeable.
Initial Value (Scaled)The Off default outputs 0, but you may set a 0 or 1.


3.2 Channel Forcing

To force a channel, view the Web Server Page, click on the icon for the channel of interest and make adjustments in the new screen that appears. Your selected channel is confirmed by the large number on the left side of the new screen. If you apply an override value, the override condition will be indicated by a simulated LED on the main Web Server Screen.

For any channel type selected, the “Forcing” screen will report information for the following read-only fields:

Channel TypeThis reports the type that you have defined for this channel.
Channel NameThis reports the name that you have specified for this channel.
StatusThis reports any of the following conditions:
Status OKInput Shorted or OpenRange High
Output OverloadInput OpenRange Low
OverrideInput Shorted

3.2.1 Analog Input Forcing

In addition to type, name and status — this screen displays the following fields:

Input ValueThis reports the Input value (read-only).
Override ValueYou can specify an Override Value.
OverrideChecking this box will put the Override Value in effect — after the Apply button is clicked. To remove the Override Value, uncheck the Override checkbox and click the Apply button.

3.2.2 Binary Input Forcing

In addition to type, name and status — this screen displays the following fields:

Input ValueThis reports the Input value (read-only) as ON or OFF.
Override ValueYou can specify an Override Value as ON or OFF.
OverrideChecking this box will put the Override Value in effect — after the Apply button is clicked. To remove the Override Value, uncheck the Override checkbox and click the Apply button.

3.2.3 Current Input Forcing

In addition to type, name and status — this screen displays the following fields:

Input ValueThis reports the Input value (read-only).
Override ValueYou can specify an Override Value.
OverrideChecking this box will put the Override Value in effect — after the Apply button is clicked. To remove the Override Value, uncheck the Override checkbox and click the Apply button.

3.2.4 Thermistor Input Forcing

In addition to type, name and status — this screen displays the following fields:

Input ValueThis read-only temperature value will be meaningless if no thermistor is connected (and Status will report Range LOW).
Override ValueYou can specify an Override Value.
OverrideChecking this box will put the Override Value in effect — after the Apply button is clicked. To remove the Override Value, uncheck the Override checkbox and click the Apply button.

3.2.5 Relay Output Forcing

In addition to type, name and status — this screen displays the following fields:

Input ValueThis reports the Input value (read-only) as ON or OFF.
Override ValueYou can specify an Override Value as ON or OFF.
OverrideChecking this box will put the Override Value in effect — after the Apply button is clicked. To remove the Override Value, uncheck the Override checkbox and click the Apply button.

4.1 Map Applet

The screen will display “Address” lines in the Unit Status box — where each line corresponds to one of the Modbus addresses of your map.

This window not only displays the Modbus mapped variables, it also displays all instances in the BAS Remote — for example, the 8 I/O channels of the BAS Remote and many of their parameters. It also allows you to view or change the preset value of most instances within the BAS Remote. This is particularly useful when you want to clear a pulse counter. It also displays the BACnet status of each instance. Having the full list of instances is handy when doing Sedona programming.

Note the following considerations:

• The screen of Figure 46 displays the situation of a BAS Remote with no Expansion Modules installed. If one Expansion Module were installed and working, the Unit Status box would list “Address 2 Online”. If two Expansion Modules were installed, the Unit Status window would list “Address 2 Online” and “Address 3 Online”. And you would see “Address 4 Online”, if you had installed a third Expansion Module.

• If a Modbus device (or an Expansion Module) has been installed but is reported as “Offline” because the Master Module has detected a communication failure and listed the questionable device as “Offline”. In such a case, you may notice that periodically the “Offline” report briefly changes to “Online”. This brief “Online” report is due to the Master Module attempt to contact the questionable device every scan cycle. Due to other considerations, the actual frequency of this “Online” report cannot be predicted — thus, you should expect brief “Online” reports at irregular intervals (but no more often than the scan cycle set by the parameters in Section 2.3).

Because Addresses 5, 6 and 7 are reserved for future use, you will not see these three addresses displayed in the Unit Status box.

4.2 Modbus Utility

This is an embedded utility that allows direct access to the Modbus registers within the BAS Remote Master, BAS Remote Expansion modules and any attached Modbus serial slave devices. It functions as a Modbus TCP client and it is an excellent utility to verify that the BAS Remote is communicating with any attached slave devices. With a web browser and an IP connection to the BAS Remote you can remotely examine and alter various Modbus register values. Access the utility by clicking the Modbus Utility button on the BAS Remote Master web page.

This screen has 5 fields, 9 radio buttons and a pair of read/write buttons. The five fields are:

Connect StatusIt initially reports "Connected to target" then awaits your first register access. As this is a Java applet, it executes on your computer. When it successfully connects to the BAS Remote, it will report “connected to target”.
NOTE: If you have uploaded a bas-cfg.csv file to the BAS Remote, you will only be able to read/write the Modbus values of the devices listed in the file. You will still be able to read/write all the Modbus registers/coils of devices not listed in the CSV file.
Slave AddressThis is 1 by default. Enter the Modbus address of the device you wish to access. To avoid erroneous results, it must be one of the following:
• the BAS Remote Master
• a BAS Remote Expansion module
• a Modbus slave device attached to the Modbus Expansion port of the BAS Remote Master
Register NumberThis is 1 by default. Enter only the least three significant digits of the address of the register you wish to access. The two most significant digits will be added automatically with a value that depends on whether you click the Read button or the Write button.
ValueThis field is used to read or write values for the register specified in the Register Number field. When writing a value, match the number format of the selected radio button or an error will result. If an error occurs, its description will be displayed in this field.
StatusThis read-only field reports the status of the most recent Modbus action. It initially reports "Connected to target" then awaits your first register access. If the attempt to read or write a register is successful, the reported status is "Success" and the Value field displays the value in question. If the attempt to access a register is unsuccessful, the Value field reports the type of error that was generated.


The five radio buttons on the left specify which number format is displayed in the Value field. The choices are:

0X:CoilUse this button if the addressed device is a Binary Output that has only two possible state values (0 or 1) — as is the case for a coil.
1X:CoilUse this button if the addressed device is a Binary Input that has only two possible state values (0 or 1) — as is the case for a coil.
4X:16-BitThis button displays the specified 16-bit register value in raw-number format.
4X:32-BitThis button displays the specified 32-bit value of a register pair in raw-number format and enables the four radio buttons on the right.
ScaledIf the specified register represents a BAS Remote I/O point, engineering units can be displayed by selecting this button. But if the register is not one of the BAS Remote I/O points, an error will result.


The four radio buttons on the right specify the number format of a 32-bit value. The choices are:

IntegerThis button specifies a whole value with no fractional content.
FloatThis button specifies a single-precision floating point value.
LOW:HIGHThis specifies Little Endian format whereby the low word occupies the base register and the high word occupies the next-higher register.
HIGH:LOWThis specifies Big Endian format whereby the high word occupies the base register and the low word occupies the next-higher register.
Read and Write buttonsClicking one of these buttons causes the specified action to occur.

4.3 Set Time

This allows you to set the unit’s time and date. This feature is most useful in Sedona control strategies.

Although you may only wish to set the Time, the screen requires values in both fields. Click the Update button when done.