Rockwell Automation DAG6.5.8 APPLICATION GUIDE SCADA SYSTEM - Manual (Page 117)

Publication AG-UM008C-EN-P - February 2005
Configuring MicroLogix 1100/1200/1500 Controllers 3-49
When the system driver is Modbus RTU Master, the following
communication port parameters can be changed.
Modbus RTU Master Configuration
Parameter Options Programming
Software Default
Channel MicroLogix 1200 FRN 8 and higher: Channel 0
MicroLogix 1100
MicroLogix 1500 FRN 9 and higher: Channel 0 or 1
0
0
0 (LSP) or 1 (LRP)
Driver Modbus RTU Master
Baud Rate 300, 600, 1200, 2400, 4800, 9600, 19.2K, 38.4K 19.2K
Parity none, even, odd none
Control Line No Handshaking, Full-Duplex Modem (RTS on), Half-Duplex Modem (RTS/CTS handshaking) No Handshaking
Inter-character
Timeout (x1 ms) 0 to 65535 (can be set in 1 ms increments); 0 = 3.5 character times
Specifies the minimum delay between characters that indicates the end of a message packet.
0
RTS Off Delay
(x20 ms)
0 to 65535 (can be set in 20 ms increments)
Specifies the delay time between when the last serial character is sent to the modem and
when RTS is deactivated. Gives the modem extra time to transmit the last character of a
packet.
0
RTS Send Delay
(x20 ms)
0 to 65535 (can be set in 20 ms increments)
Specifies the time delay between setting RTS until checking for the CTS response. For use
with modems that are not ready to respond with CTS immediately upon receipt of RTS.
0
Pre Transmit Delay
(x1 ms)
0 to 65535 (can be set in 1 ms increments)
When the Control Line is set to No Handshaking, this is the delay time before transmission.
Required for 1761-NET-AIC physical Half-Duplex networks. The 1761-NET-AIC needs 2 ms of
delay time to change from receive to transmit mode.
When the Control Line is set to Half-Duplex Modem or Full-Duplex Modem, this is the
minimum time delay between receiving the last character of a packet and the RTS assertion.
0