Owner's manual

FOUNDATION
TM
Fieldbus Blocks Manual
6-4
Block Errors
The following conditions are reported in the BLOCK_ERR attribute:
Simulate active – SIMULATE_D is enabled; therefore, PV_D
is not real.
Input failure/process variable has Bad status – The readback
value is bad.
Output failure – The output hardware or the configured channel is
invalid.
Readback failed – The hardware providing readback is bad.
Out of service – The block is not being processed.
Modes The DO block supports the following modes:
Manual (Man) – The block output (OUT_D) may be entered manually.
Automatic (Auto) – The block algorithm uses the local setpoint value
(SP_D) to determine OUT_D.
Cascade (Cas) – The block uses a setpoint supplied by another function
block.
RemoteCascade (RCas) – The block uses a setpoint supplied by a host
computer.
Out of Service (O/S) – The block is not processed and the output is not
transferred to I/O. The BLOCK_ERR attribute shows Outofservice.
Status Handling / Action
on Failure
Under normal operating conditions, the output statuses (OUT_D and
BKCAL_OUT_D) are Good: Cascade. If the output hardware fails, the
status of BKCAL_OUT_D is set to Bad: DeviceFail, and the
BLOCK_ERR attribute shows Output Failure. If the hardware used for
output feedback fails, the status of READBACK_D and PV_D is set to
Bad: DeviceFail, and the BLOCK_ERR attribute shows Bad PV and
Readback Failed.