Watlow Controls MICRODIN Temperature Controller
Problem Solution Overview
We performed testing between the subject device and ProSoft Technology's 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 3,4, 6 & 16
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 performed 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
|
5
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
|
N7:10
|
1
|
1
|
5
|
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
Code
|
3
Source
Address
|
4
Count
|
5
Dest.
Address
|
6
Read
Type
|
7
Polling
Time Preset
|
|
N7:50
|
1
|
1
|
3
|
1
|
10
|
0
|
0
|
0
|
|
N7:60
|
1
|
1
|
4
|
304
|
2
|
10
|
0
|
0
|
|
N7:80
|
5
|
1
|
6
|
200
|
1
|
304
|
0
|
0
|
|
N7:90
|
5
|
1
|
16
|
201
|
1
|
305
|
0
|
0
|
Our test command list perfoms the following functions.
- N7:50 Read 10 registers starting at 1
- N7:60 Read 2 registers starting 304
- N7:70 Conditional write to register 304
- N7:80 Conditional write to register 305
Cable Connection:
The physical connection which was used during testing was as follows:
|
3100-MCM Module
|
|
MicroDin
|
|
14 TxRxD+
|
--------------------------------
|
Yellow (D)
|
|
25 TxRxD-
|
--------------------------------
|
Green (C)
|
|
7 GND
|
--------------------------------
|
Red (B)
|
|
4 RTS
|
----------|
|
|
|
5 CTS
|
----------|
|
|
See Additional comments
Additional Comments and Observations:
- This is the termination point on the RJ11 connector used to interface with the unit as referenced in the user manual for the unit. Please refer to the user manual for the MicroDin for exact details.
- The read length is limited to 32 registers.
- The write length is limited to 1 register.
|
