ProSoft Technology MVI56-AFC - Manual (Page 296)

Reference MVI56-AFC ♦ ControlLogix Platform
User Manual Liquid and Gas Flow Computer
Page 296 of 316 ProSoft Technology, Inc.
February 25, 2011
14.7 Modbus Port configuration
Configuration of the serial ports is stored in these blocks of the Modbus table:
Address Type Description
Ph00102 to Ph00105 Bm Port 1 configuration
Ph00106 to Ph00109 Bm Port 2 configuration
Ph00110 to Ph00113 Bm Port 3 configuration
Each group of registers specifies configuration of the corresponding serial port.
The four registers of each block are interpreted as follows:
Ofs Type Tag Contents
+0 Bm Uart UART parameters and port options
+1.L By TmoC LSB: Timeout for CTS
+1.H By TmoR MSB: Master mode receive timeout
+2 By Dly1 Delay before first data after CTS
+3 By Dly0 Delay after last data before ~RTS
The CTS timeout and both delays are in units of 5ms (200Hz system clock), with
valid values from 0 thru 255, and are significant only for transmission of outgoing
Modbus messages. The receive timeout is in units of 0.1 second, with valid
values from 0 thru 255 (where 0 implies the default of 5, that is, one-half second),
and is significant only for the last port when configured as a Modbus master. The
UART parameters and port options word is a bitmap:
Bit Parameter Value
bits 0 to 2 Baud 000: none; see below
001: 300 baud
010: 600 baud
011: 1200 baud
100: 2400 baud
101: 4800 baud
110: 9600 baud
111: 19200 baud
bits 3 to 4 Parity 00: no parity
01: odd parity
10: even parity
11: no parity (should not be used)
bit 5 Data bits 0: 8 data bits
1: 7 data bits
bit 6 Stop bits 0: 1 stop bit
1: 2 stop bits