ProSoft Technology MVI56E-MCM/MCMXT - Manual (Page 11)

MVI56E-MCM ♦ ControlLogix Platform Start Here
Modbus Communication Module User Manual
ProSoft Technology, Inc. Page 11 of 199
June 18, 2014
The MVI56E-MCM module can transfer a maximum of 10,000 (16-bit)
registers to and from the ControlLogix processor. The Sample Ladder
transfers 600 words to the ControlLogix processor (into the Read Data array),
and obtains 600 words from the ControlLogix processor (from the Write Data
array)
5 ____________ Will you be using the module as a Modbus Master or Modbus
Slave? Will you be transferring data using Modbus RTU or Modbus ASCII?
Modbus is a Master/Slave network. Only one Master is allowed on the serial
communications line (max 32 devices/RS485). The Master is responsible for
polling data from the Slaves on the network.
6 ____________ For a Modbus Master, what Slave Device Addresses and
Modbus Data Addresses do you need to exchange data with on the Modbus
network?
For a Modbus Master, you must know the Slave Device Address number of
each Slave device to poll. You also need the Modbus address (for example,
coil 00001, register 40001) of the data to read from or write to each Slave
device.
7 ____________ For a Modbus Slave, how many words or bits of data do you
need to send to the Master device?
The MVI56E-MCM module can send data to a Modbus Master as 0x coil
data, 1x input coil data, 3x input registers, and 4x holding registers. The
sample program transfers 600 (16-bit) words or 9600 bits to the ControlLogix
processor, and 600 (16-bit) words or 9600 bits from the ControlLogix
processor.
8 Serial Communication Parameters for the Modbus network:
____________ Baud rate?
____________ Data bits?
____________ Parity?
____________ Stop bits?
Required for both Master and Slave configurations.
9 ____________ Wiring type to use (RS232, 422 or 485). Configured by
Setting Jumpers.
Required for proper implementation of the module in Master and Slave
configurations.
Note: If you are using RSLogix 5000 version 16 or newer, refer to Before You Import the Add-On
Instruction (page 15).
For RSLogix 5000 version 15 and earlier, refer to Using the Sample Program - RSLogix 5000
Version 15 and earlier (page 180).
Most applications can use the Sample Ladder Logic without modification.