Appendix E - Exception Codes; Appendix F - Run Indicator - Siemens SITRANS F M MAGFLO series Operating Manual

Modbus RTU RS-485
APPENDIX E
Exception codes
APPENDIX F
Run Indicator
APPENDIX E & F
The Modbus module uses the following Modbus exception codes, when responding to a master
module:
Exception code (Dec)
01
02
03
04
06
If an exception code 04 is received, further requests have to be done to narrow down the exact
problem.
If any doubts about the address that failed, „Last Coil/HoldReg ErrorAddr" can be read. This will
return the faulty address.
Modbus Modbus
register address
4:00681 680
4:00682 681
4:00683 682
4:00684 683
Reading „Last Coil/HoldReg ErrorNo" will return a detailed error reason. A list of error numbers
can be seen below.
Error Error
Number Number
(Dec) (Hex)
3 3
4 4
5 5
127 7F
The Run Indicator indicates the state of the device. Two states are possible: ON (0xFF) and OFF
(0x00). The device will be in state ON, unless a serious error is present.
The following errors can turn the state to OFF:
•
When a „Fatal Error" is active on the „Error Pending List"
•
Boot up problems when powering up the flowmeter.
•
If no measurement are delivered or the time between them is too high.
The last condition will be based on the following:
Only the internally broadcasted flow-value is checked. The expected broadcast-rate is read at
power up. If a broadcast is not received after 10 times the expected broadcast rate, the broadcast
rate is re-read from the USM (it may have been changed since power up). If the broadcast rate
was not changed (and the rate was not zero), the Run Indicator is set OFF. Reception of ten
broadcasted (flow-) values within 10 times the expected window will set the run-indicator TRUE
again.
SFIDK.PS.023.D2.02
Exception name
Illegal function
Illegal data address
Illegal data value
Slave device failure
Device busy
No. of Data
bytes type
2 Word
2 Word
2 Word
2 Word
Error name
Write access denied
Max. limit
Min. limit
No error
Description
Last Coil ErrorAddr
(Modbus cmd: 1 or 5)
Last Coil ErrorNo
(127 = No error)
Last HoldReg ErrorAddr
(Modbus cmd: 3 or 16)
Last HoldReg ErrorNo
(127 = No error)
Reason
This parameter is in a state where it is
not writable
The value was greater than the allowed
maximum value
The value was less than the allowed
minimum value
No problem
Read/
write
R
R
R
R
33