Rockwell Automation 1755-OF8 GuardPLC Controller Systems - Manual (Page 278)

278 Publication 1753-UM001C-EN-P - March 2010
Chapter 22 Communicate with Modbus and Profibus Devices
Follow these steps to connect signals.
1. Expand Protocols, right-click the Modbus Slave icon, and choose
Connect Signals .
2. Edit the signals you want to receive or send.
•
Use the Inputs tab to determine which values to read into the
controller.
•
Use the Outputs tab to define output values to send to the
Modbus master. Signals in the output tab must match the
order of signal types requested by the Modbus master.
•
Associate each input or output with a signal from the signal
editor. You can drag and drop signals from the signal editor
to the signal connections dialog box.
The Modbus function calls must match the order in which the signal
offsets appear. For example, if you want to read 3 Boolean signals
followed by 4 Registers, the first 3 signals must be BOOL and the next
4 must be INT signals.
If you want to Click this tab
create a new signal New Connected Signal
renumber offsets sequentially for all signals New Offsets
delete the selected signal Delete Connected Signal
TIP
The output section automatically sorts the name field based on alphanumerical order. This does not
automatically change the offsets, but if you renumber after sorting, the offsets will change and there is
no undo feature. This changes the order in which the signals are sent out the serial port.
Because names are used only in printouts, you may want to enter these names in alphanumeric order
to begin with. (For example signal 101, signal 102, signal 103, signal 104, and so forth.)