Yokogawa Data Acquisition with PID Control CX2000 - Manual (Page 114)

1-102
IM 04L31A01-01E
FAIL/Memory End Relay Output (/A4F option or /A4FR option)
FAIL Output
When a failure occurs in the CPU of the CX2000, a relay contact signal (1 signal) is
output.
The relay is energized when the CPU is normal; it is de-energized when a CPU failure
occurs (de-energized on failure). Therefore, relay output is carried out also when the
power is turned OFF (including a power failure) (see figure below). You cannot change
this behavior.
The following figure shows the operation of the FAIL output relay (de-energized type).
NO C NC
During normal operation
NO C NC
When a failure occurs
NO C NC
When power is turned OFF
* NO, C, and NC are names of the relay output terminals.
NO: Normally Opened, C: Common, NC: Normally Closed
Memory End Output
When the remaining free space in the internal memory or external storage medium
becomes small, a relay contact signal (1 signal) is output. When a memory end is
detected, the relay is energized (energized on memory end). You cannot change this so
that it is de-energized on memory end. When memory end is output, save the data to an
external storage medium (during manual save mode) or change the external storage
medium (during auto save mode).
The memory end output operates as follows:
• During auto save mode
If an external storage medium is inserted in auto save mode, the relay is energized
when the remaining free space on the external storage medium falls to 10%. (At this
point, the icon indicating the status of the external storage medium in the status
display section turns from green to red.)
• During manual save mode
• If the type of data to be saved is display data only or display data and event data,
the relay is energized when the remaining amount of time for acquiring the display
data in the internal memory falls to the specified time.
• If the type of data to be saved is event data only
If the CX2000 is in a mode in which data acquisition to the internal memory starts
at the same time as the start of measurement, the relay is energized when the
remaining amount of time for acquiring the event data falls to the specified time.
If the CX2000 is in a mode in which the data acquisition to the internal memory is
started using a trigger such as an alarm occurrence, the relay is not energized (no
memory end output).
The following figure shows the operation of the memory end output relay (energized on
memory end).
NO C NC
During normal operation
NO C NC
When memory end occurs
NO C NC
When power is turned OFF
1.20 Other Functions