GE Hydran 201i - Page 248

MA-033 Rev. 14.0, 12-Nov-18
Hydran* 201i Instruction Manual
Page 248
Request
Function Code
1 byte
01h
Starting Address
2 bytes
0000h to FFFFh
Quantity of Coils
2 bytes
1 to 2,000 (07D0h)
Response
Function Code
1 byte
01h
Byte Count
2 bytes
N *
Coils Status
n bytes
n = N or N + 1
Error
Error Code
1 byte
81h
Exception Code
1 byte
01 or 02 or 03 or 04 or 06
Table J - 5: Format for the Read Coils (01h) / Read Discrete Inputs (02h)
* N = Quantity of Output / 8, if the remainder is different of 0 --> N =N + 1
Table J-6 below presents, as an example, the reading of discrete outputs with the
address range 20–38. The starting address must be specified, followed by the quantity
to read. The return, in LSB format, can be seen in Table J-7 that follows.
Request
Response
Field Name
(hex)
Field Name
(hex)
Function
01
Function
01
Starting Address Hi
00
Byte Count
03
Starting Address Lo
13
Output Status 27–20
CD
Quantity of Outputs Hi
00
Output Status 35–28
6B
Quantity of Outputs Lo
13
Output Status 38–36
05
Table J - 6: Reading of Discrete Outputs with the Address Range 20-38
1st word
2nd word
X+15
X+14
X+13
...
X+3
X+2
X+1
X *
X+31
…
Table J - 7: Return in LSB Format
* X = Starting address