ICP DAS, MDC-211-WF user manual , v1.1 Page
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Figure 5.2 Modbus command real-time status example
For example of Figure 5.2 above, Modbus Master uses the function code 04 to read the
connection status from 39600 as Table 5.1.
Table 5.1 The corresponding Internal Register address of the command status
Command No. Addresses State Code
Web Page Display
#001
39600
00 00
GOOD
#002
39601
83 02
ILLEGAL DATA ADDRESS
#003
39602
83 03
ILLEGAL DATA VALUE
#004
39603
FF 00
DISABLED
#005
39604
FF FF
TIMEOUT
The descriptions for the Read status:
-
0: Indicates that the connection is in normal status.
-
0xFFFF: Connection Timeout
-
0xFF00: Command not enabled (Disabled)
-
0x8XYY: Communication error. X-function code, YY– Error code, as Table 5.3 below