Manual

Chromalox Instruments and Controls
A-51643 Rev. 6 10/06/03 22
Response
The output status in the response is packed as one output per bit of the data field. Status is indicated as 0
= Off, 1 = On. The LSB of the first data byte contains the output addressed in the query. The other
outputs follow toward the high order end of this byte, and from low order to high order in subsequent
bytes. If the returned output quantity is not a multiple of eight, the remaining bits in the final data byte
will be padded with zero (toward the high order end). The Byte Count field specifics the quantity of
complete bytes of data.
Example response:
Field Name
Data
Slave address
$11
Function
$01
Byte count
$05
Data (outputs 27 . . . 20)
$CD
Data (outputs 35 . . . 28)
$A0
Data (outputs 43 . . . 36)
$36
Data (outputs 51 . . . 44)
$FB
Data (outputs 56 . . . 52)
$05
CRC
$----
5.2.2 [02] Read Input Discretes
Class 1 command. Reads the On/Off status of discrete inputs in the slave. Broadcast is not supported.
Query
The query message specifies the starting input and quantity of inputs to be read. Inputs are addressed
starting at 0.
Example: Request to read inputs 1 . . . 7 from slave address 8.
Field Name
Data
Slave address
$08
Function
$02
Starting address hi
$00
Starting address lo
$00