Installation manual

Publication 1747-RM001G-EN-P - November 2008
SLC Communication Channels 13-93
The Baud defaults to 19200.
The Control Line can be configured as:
• No Handshaking
• Full-Duplex Modem
• Half Duplex without Continuous Carrier
The Protocol Control defaults are:
• No Handshaking
• InterChar. Timeout = 0
• Pre Transmit Delay = 0.
When the system driver is Modbus RTU Master, the following communication
port parameters can be changed:
Table 13.26 Modbus RTU Master Channel Configuration Parameters
Parameter Options Programming
Software Default
Channel Channel 0 0
Driver Modbus RTU Master
Baud Rate 110, 300, 600, 1200, 2400, 4800, 9600, 19.2K, 38.4K 19.2K
Parity none, even, odd none
Control Line No Handshaking, Full-Duplex Modem, Half-Duplex without Continuous Carrier 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 or Full-Duplex Modem, 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, this is the minimum time delay before
RTS assertion.
0
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