Rockwell Automation 937CU-AISTR-DC1 Strain Gauge Converter Installation Instructions - Manual (Page 42)

The commands must be encoded as follows:
The
Strain Gauge Converter returns the following responses:
Explanations:
• Address: The address must be calculated as follows: 128 + setting under Service
→ RS 485 (see
section 7.8). Values from 128 + 0 to 128 + 31, i. e. from 10000000
Bin
to 10011111
Bin
, are possible.
• Checksum: The checksum is calculated as follows: 100
Hex
- (1
st
byte + ... + penultimate byte of the
code), e. g. for Check_1 for address 17: 100
Hex
- (91
Hex
+ 1) = 6E
Hex
= 01101110
Bin
• The figure 9 in the response to Check_1 refers to the device type
Strain Gauge Converter.
• Value: in the signed long data format (4 bytes or 2 bytes)
Command 1
st
byte 2
nd
byte 3
rd
byte 4
th
byte 5
th
byte 6
th
byte
Null 0 0 0 0 0 0
Check_1 Address 1 Checksum
Get_value_ch1 Address B
Hex
Checksum
Get_value_ch2 Address C
Hex
Checksum
Get_value_ch3 Address 10
Hex
Checksum
Get_current Address D
Hex
Checksum
Command 1
st
byte 2
nd
byte 3
rd
byte 4
th
byte 5
th
byte 6
th
byte
Check_1 Address 9 Checksum
Get_value_ch1 Address Value Checksum
Get_value_ch2 Address Value Checksum
Get_value_ch3 Address Value Checksum
Get_current Address Value Checksum
Bul. 937
C Strain Gauge Converter Installation Instructions
40