OPERATION ST100A Series Flow Meter
74 Fluid Components International LLC
Table 16 – Command Status Bytes, Bit Assignments
Byte Bit
Cmd-Specfic Response Code (No Comm Error)
Reserved – Bit cleared to zero.
1
Buffer Overflow – The message was too long for the
received buffer of the device.
Reserved – Bit cleared to zero.
3
Longitudinal Parity Error – The longitudinal parity
calculated by the device did not match the check byte at
Byte 0 4
Framing Error – The stop bit of one or more bytes received
by the device was not detected by the UART (i.e., a mark or 1
was not detected when a stop bit should have occurred).
Command-Specific Response Code (0-127)
See Table 17 below.
5
Overrun Error – At least one byte of data in the receive
buffer of the UART was overwritten before it was read (i.e.
the slave did not process incoming byte fast enough).
6
Vertical Parity Error – The parity of one or more of the bytes
received by the device was not odd
1: Set bit means byte represents communications error.
0: Cleared bit means byte represents response code.
Primary Variable Out of Limits – The PV is beyond its operating limit.
Non-Primary Variable Out of Limits – A device variable not mapped to the PV is beyond its operating limits.
2
Loop Current Saturated – The loop current has reached its upper (or lower) endpoint limit and cannot increase (or
decease) any further.
Loop Current Fixed – The loop current is being held at a fixed value and is not responding to process variations.
4
More Status Available – More status information is available. Refer to Command 48, Additional Device Status
Bytes, page 75.
Cold Start – A power failure or device reset has occurred.
Configuration Changed – An operation was performed that changed the device’s configuration.
Device Malfunction – The device detected a serious error or failure that compromises device operation.
Table 17 – Command-Specific Response Codes
(Success) No command-specific errors
(Error) Upper Range value too low/Invalid mode
(Error) Invalid selection/Invalid Poll Address
(Error) Upper and Lower Range values out of
limit
(Error) Passed parameter too large
(Warning) Span too small/Status byte mismatch
(Error) Passed parameter too small
(Mode Error) Access restricted
(Error) Too few data bytes received
(Error) Invalid units code
(Misc Error) Device-specific command error
(Mode Error) In Write-Protect mode
(Error) Command response truncated
(Error) Invalid date code/Configuration change
counter mismatch/Lower range value too
high/Incorrect loop current mode or value
(Error) Lower Range value too low
(Error) Command not implemented
(Error) Upper Range value too high/Loop
current not active (device in multidrop mode)