Barber-Colman 7EC/7SF Controllers Connectivity to 3100-MCM
Problem Solution Overview
We performed testing between the subject device and our 3100-MCM product.
Solution Brief
Our testing generated the following results:
- We were able to successfully communicate with the device. (see below for configuration parameters used during the testing)
- The product supported Modbus functions 1,2,3,4,5,6,15 & 16 0.
The purpose of our testing is to assure a level of compatibility in the communications between the two products. Through this testing, we attempt to identify problem areas that may arise when implementing the interface in the field.
Configuration:
The product testing was perfomed with the following settings used:
- Baud: 19200
- Parity: None
- Stop: 1
- Mode: RTU Master Mode
- Physical Connection : RS-485
The Module Configuration used in our testing was as follows:
|
Address
|
0
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
9
|
|
N7:0
|
0
|
0
|
6
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
|
N7:10
|
1
|
1
|
6
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
|
N7:20
|
4
|
1
|
2
|
130
|
150
|
0
|
0
|
0
|
4
|
0
|
This configuration, in combination with the example ladder logic referenced below, generates the following memory map:
N10:0 to N10:129 - Slave Data
N10:130 to N10:149 - Slave Error Table (Contains revision level information also)
N10:150 to N10:199 - Master Error Table (Contains status of commands for diagnostics)
Command List:
The following command list shows some of the commands which were used to test the communications:
|
Address
|
0
Port
Number
|
1
Slave
Number
|
2
Function
Mode
|
3
Source
Number
|
4
Count
|
5
Dest.
Address
|
6
Read
Type
|
|
N7:50
|
1
|
1
|
1
|
218
|
1
|
0
|
0
|
|
N7:60
|
1
|
1
|
2
|
1
|
1
|
1
|
0
|
|
N7:70
|
1
|
1
|
3
|
1
|
5
|
10
|
0
|
|
N7:80
|
1
|
1
|
5
|
3200
|
1
|
218
|
0
|
|
N7:90
|
1
|
1
|
6
|
201
|
1
|
1
|
0
|
Our test command list perfoms the following functions.
- N7:50 Read local / remote control bit register.
- N7:60 Read auto / manual bit register.
- N7:70 Read set point, PID out, proprotional band, integral time value and derivative time value.
- N7:80 Write to local / remote control bit register.
- N7:90 Write to set point register.
Cable Connection:
The physical connection which was used during testing was as follows:
|
3100-MCM Module
|
|
7EC
|
|
14 TXD
|
--------------------------------
|
Terminal 10
|
|
25 RXD
|
--------------------------------
|
Terminal 11
|
|
7 GND
|
--------------------------------
|
Terminal 9
|
|
3100-MCM Module
|
|
7SF
|
|
14 TXD
|
--------------------------------
|
Terminal 11
|
|
25 RXD
|
--------------------------------
|
Terminal 12
|
|
7 GND
|
--------------------------------
|
Terminal 13
|
Additional Comments and Observations:
- Maximum length for function 3 & 4 is 20 words. Lengths greater then 20 will result in the controller returning an error 9.
- The Modbus addresses used in the product documentation should be used directly.
- The unit must be removed from its case to be placed into configuration mode.
|
