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7ML19985CN01
Milltronics SF 500 - INSTRUCTION MANUAL
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SF 500 uses the following exception codes:
Error Handling
Errors can be divided up into two general sources. Either:
1.
There is an error in transmission
or
2.
The user tries to do something that is not a valid action
In the first case, the SF 500 will, not respond and let the master wait for a response time
out error, which will cause the master to re-send the message.
In the second case, it depends on what the user tries to do. Listed below are various
actions and what the expected outcome is. In general, SF 500 will not give an error to the
user request.
•
If the user reads an invalid parameter, the user will get a number back.
•
If the user writes an invalid parameter (a non-existing parameter or a read only
parameter), the value will be ignored and no error response will be made. However,
the current value will not reflect the desired new value.
•
If the user writes a read only register, then the value will be ignored and no error
response will be made. However, the current value will not reflect the desired new
value.
•
If the user attempts to write one or more registers that are out of range, an
exception response code 2 will be generated.
•
If using an unsupported function code, undocumented results may occur. The user
is encouraged not to do this.
Code
Name
Meaning
01
Illegal Function
The function code received in the query is not an
allowable action for the slave.
02
Illegal Data Address
The data address received in the query is not an
allowable address for the slave.
03
Illegal Data Value
A value contained in the query data filed is not an allow-
able value of the salve.
04
Slave Device Failure
An unrecoverable error occurred while the slave was
attempting to perform the requested action.
05
Acknowledge
The slave has accepted a request and is processing it,
but a long duration of time is required.
06
Slave Device Busy
The slave is processing a long-duration program com-
mand.
08
Memory Parity Error
The slave attempted to read extended memory, but
detected a parity error in the memory. Service may be
required on the slave.