ICC XLTR-1000 Instruction Manual page 42

ICC
Read Enable and Function Code Selection
Check Read to enable reading (the service object will continuously read from the
remote device unless a pending Write exists). When reads are enabled, the
desired read Function Code can be selected in the drop-down box.
Write Enable and Function Code Selection
Does not apply to input objects. Check Write to enable writing (when values
encompassed by this service object change in the gateway's database, these
changes will be written down to the targeted remote device). When writes are
enabled, the desired write Function Code can be selected in the drop-down box.
Priority
This field is used to specify the priority associated with writes for this service
object. Select the desired priority from the dropdown menu.
Service Object Status
If it is desired to reflect the status of this service object, check the Reflect Status
checkbox and enter a database address between 0 and 4080 (0x0 – 0xFF0) at
which to store the status information. For more information on reflecting the
status of service objects, refer to section 8.4.2.
8.6.3.4 Configuration Example
This example will configure the gateway for end-to-end communication using
BACnet MS/TP client and Modbus RTU slave.
Say, for instance, we wish to communicate to an adjustable-speed drive that
supports BACnet MS/TP from a PLC that supports Modbus RTU. We wish to
monitor the output frequency, output current, and output voltage of the drive,
located at analog input objects 1, 2 and 3, with multipliers of 0.01, 0.01, and 0.1
respectively. We'd also like to monitor the running, forward/stop, and reverse/stop
bits, located at binary input objects 1, 2 and 3, respectively. To run the drive, we
need to be able to command the frequency command at analog output object 2
with a multiplier of 0.01, the command forward/stop bit at binary output object 2,
and command reverse/stop bit at binary output object 3.
Configure the "RS-485 A" port (Modbus slave) using the above requirements
• Connect the gateway to the PC via a USB mini type-B cable.
• Open the configuration utility and select the XLTR-1000 (see section 8.1 for
more information on selecting a device).
• Click on the RS-485 A Configuration tab.
• Select Modbus RTU Slave from the protocol dropdown menu.
• Enter the Baud Rate and Parity settings to match that of the PLC.
• Enter the slave address that your PLC is configured to communicate with
into the Address field.
• The default mapping of the gateway's database into the Modbus register
space will be used, so no register remap objects need to be created.
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