ProSoft Technology MVI56-AFC User 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