Rockwell Automation 1755-OF8 GuardPLC Controller Systems - Manual (Page 277)

Publication 1753-UM001C-EN-P - March 2010 277
Communicate with Modbus and Profibus Devices Chapter 22
2. Expand Protocols, right-click the Modbus Slave icon, and choose
Properties.
Connect Signals
The Modbus RTU Slave protocol lets you read data from the
GuardPLC controller and write data to the GuardPLC controller, but
none of this data can be used for safety functions.
Inputs are signals sent from the Modbus master to the controller
(slave). Outputs are signals sent from the controller (slave) to the
master.
For this field Specify
Slave Address the slave address (1…247) of the controller. The Modbus protocol of the controller supports only a
direct point-to-point connection between the master and slave.
The controller is always configured as slave. It transfers process values via the serial interface to
the master only when it receives the corresponding request from the master.
Interface the field bus interface to be used by the Modbus Slave protocol (comm1, comm2, comm3).
Choose comm1 for GuardPLC 1600 or 1800 controllers.
Refresh Rate Refresh rate in ms for non-safe communication. The default is 0, the fastest refresh rate.
Baud Rate the data transfer speed in bits/s. Choose from a pull-down menu of predefined values between
300 and 115,200 bps. The default baud rate is 9600 bps.
Parity the parity for the recognition of transfer errors. Choose No, Odd, or Even. The default is No parity.
Stop Bit either 1 or 2 stop bits for the serial data transfer. The default is 1 stop bit.