Schweitzer SEL2020
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 & 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: 9600
- Parity: None
- Stop: 2
- Mode: RTU Master Mode
- Physical Connection : RS-232
The Module Configuration used in our testing was as follows:
|
Address
|
0
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
9
|
|
N7:0
|
4096
|
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
|
0
|
4
|
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
|
1
|
4096
|
160
|
0
|
0
|
10
|
|
N7:60
|
1
|
1
|
2
|
4096
|
160
|
10
|
0
|
10
|
|
N7:70
|
1
|
1
|
3
|
8192
|
5
|
20
|
0
|
10
|
|
N7:80
|
1
|
1
|
4
|
2400
|
5
|
30
|
0
|
10
|
|
N7:90
|
9
|
1
|
5
|
3200
|
1
|
4256
|
0
|
0
|
|
N7:100
|
9
|
1
|
6
|
200
|
0
|
2077
|
0
|
0
|
|
N7:110
|
9
|
1
|
16
|
201
|
1
|
2073
|
0
|
0
|
Our test command list perfoms the following functions.
- N7:50 Read 160 bits starting at bit 1000H.
- N7:60 Read 160 bits starting at bit 1000H.
- N7:70 Read 2000H - 2004H.
- N7:80 Read 960H - 964H.
- N7:90 Write to port breaker 10A0H.
- N7:100 Write to command _reg 081DH.
- N7:110 Write to SBO_REGS 0819H.
SEL 2020 configured registers
Below is a listing of the available registers configured during testing using SEL-501 relay as data source.
|
Data Item
|
Starting Address
|
Type
|
|
_YEAR
|
2000h
|
int
|
|
DAY_OF_YEAR
|
2001h
|
int
|
|
TIME(ms)
|
2002h
|
int[2]
|
|
MONTH
|
2004h
|
char
|
|
DATE
|
2005h
|
char
|
|
YEAR
|
2006h
|
char
|
|
HOUR
|
2007h
|
char
|
|
MIN
|
2008h
|
char
|
|
SECONDS
|
2009h
|
char
|
|
MSEC
|
200Ah
|
int
|
|
IAX
|
200Bh
|
float[2]
|
|
IBX
|
200Fh
|
float[2]
|
|
ICX
|
2013h
|
float[2]
|
|
IAY
|
2017h
|
float[2]
|
|
IBY
|
201Bh
|
float[2]
|
|
ICY
|
201Fh
|
float[2]
|
|
IAB1(A)
|
2023h
|
float[2]
|
|
IBC1(A)
|
2027h
|
float[2]
|
|
ICA1(A)
|
202Bh
|
float[2]
|
|
IAB2(A)
|
202Fh
|
float[2]
|
|
IBC2(A)
|
2033h
|
float[2]
|
|
ICA2(A)
|
2037h
|
float[2]
|
|
I0_1(A)
|
203Bh
|
float[2]
|
|
I1_1(A)
|
203Fh
|
float[2]
|
|
I2_1(A)
|
2043h
|
float[2]
|
|
I0_2(A)
|
2047h
|
float[2]
|
|
I1_2(A)
|
204Bh
|
float[2]
|
|
I2_2(A)
|
204Fh
|
float[2]
|
|
|
|
Data Item
|
Starting Address
|
Type
|
|
_YEAR
|
2800h
|
int
|
|
DAY_OF_YEAR
|
2801h
|
int
|
|
TIME(ms)
|
2802h
|
int[2]
|
|
TARGET
|
2804h
|
char[10]
|
SEL-2020 port setup
Cable Connection:
|
3100-MCM
Module
|
|
SEL 2020
Port 16
|
|
2 TXD
|
----------------
|
Pin 2
|
|
3 RXD
|
----------------
|
Pin 3
|
|
7 GND
|
----------------
|
Pin 5
|
|
4 RTS
|
--------|
|
|
|
5 CTS
|
--------|
|
|
Additional Comments and Observations:
- Polling time presets were used in the testing.
- Control command was used for all write instructions.
|
