Q5: How To Read The Status Of Each Connection - ICP DAS USA MDC-700 Series User Manual

Q5: How to read the status of each connection?
A5: The status for each connection is saved in the sequence of polling definition from local register
address 39600. The maximum number of polling definition in the config.csv file is 240, so the
available address for the connection status is from 39600 to 39839. A Modbus master use
function code 04 to read the status, up to 126 register of status can be read in one command.
For example, the status of the graph shown above is presented as the third column in the
following table.
Def. number Address
Def.#001
Def.#002
Def.#003
Def.#004
Def.#005
Def.#006
The value of status:
0: Good
0xFFFF: Timeout
0x8XYY: Exception Rresponse. X ‐ Modbus Function Code. YY ‐ Exception Code.
Exception Name
Code
01 Illegal Function
02 Illegal Data Address
03 Illegal Data Value
04 Illegal response
length
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Status
39600 0
39601 0
39602 0xFFFF
39603 0x8201
39604 0
39605 0x8402
Status display on web page
GOOD
GOOD
TIMEOUT
ERROR: ILLEGAL FUNCTION
GOOD
ERROR: ILLEGAL DATA ADDRESS
Meaning
The function code received is not an allowable action.
The data address received in the query is not an
allowable address.
A value contained in the query data field is not an
allowable value.
The request would generate a response with size bigger
than that available for MODBUS protocol.