ProSoft Technology PTQ-AFC - Manual (Page 89)

PTQ-AFC ♦ Modicon Quantum Platform Quick Start
Liquid and Gas Flow Computer for Hydrocarbon Products User Manual
ProSoft Technology, Inc. Page 89 of 259
June 23, 2011
6.9.4 Modbus Pass-Through
The Modbus pass-through feature allows you to configure a Modbus pass-
through region in the Virtual Slave (Project / Site Configuration). After the
module receives a holding register write command (Modbus functions 6 or 16) or
a bit write command (Modbus functions 5 or 15) to this region, it will generate a
pass-through block to be sent to the processor containing the Modbus command
data. You may define a word pass-through region (for Modbus functions 6 and
16) and a bit pass-through region (for Modbus functions 5 and 15).
Important: You must enable the virtual slave by configuring a Modbus address greater than 0
(Project / Site Configuration).
You can control which communication ports will support the pass-through
(Project / Site Configuration / Port X button).
This feature requires ladder logic to read the pass-through block from the module
to the processor. Refer to the Ladder Logic section for more information about
the pass-through feature.