ProtEX-MAX PD8-6210 Explosion-Proof Analog Input Batch Controller
Instruction Manual
45
Setting the Relay Action
Operation of the relays is programmed in the
Action
menu. The relays are commonly set up for any of the
following modes of operation:
1. Always set to Auto for Batch control operation.
Also for automatic reset (non-latching) of alarms.
2. Sampling (the relay is activated for a
user-specified time)
3. Off (relay state can be controlled by Interlock
feature)
In addition, the following relay actions may be
programmed. These actions are not appropriate for
batch control applications but may be used when the
controller is in other applications.
4. Aut manual reset when not in a batch
process (non-latching)
5. Latching (manual reset only, when not in a batch
process)
6. Latching with Clear (manual reset only when not
in a batch process after alarm condition has
cleared)
7. Pump alternation control (not applicable to batch
control)
Setting Batch Control Relays
Operation of batch control relays are programmed in
the
Assign
menu by selecting
total
as the assignment.
Relays set to
total
beyond the first relay will include a
pre-close parameter (
precls
) option. Selecting
yes
for
precls
will enable multi-stage batching with pre-close,
and the valve will close prior to the end of the batch at
volume equal to the preset value minus the pre-close
amount entered. Selecting
no
for
precls
will have the
relay perform identically to the first batch control relay
set to
total
.
Programming Alarm Set and
Reset Points
High alarm: program set point above reset point.
Low alarm: program set point below reset point.
The deadband is determined by the difference
between set and reset points. Minimum deadband is
one display count. If the set and reset points are
programmed with the same value, the relay will reset
one count below the set point.
Note:
Changes are not saved until the reset point has been
accepted.
Setting Fail-Safe Operation
In fail-safe mode of operation, the relay coil is
energized when the process variable is within safe
limits and the relay coil is de-energized when the
alarm condition exists. The fail-safe operation is set
independently for each relay. Select
on
to enable or
select
off
to disable fail-safe operation. Failsafe
mode should not be used on batch relays assigned to
total.
Programming Time Delay
The
On
and
Off
time delays may be programmed for
each relay between 0 and 999.9 seconds. The relays
will transfer only after the condition has been
maintained for the corresponding time delay.
The
On
time delay is associated with the set point.
The
Off
time delay is associated with the reset point.
Relay Action for Loss of 4-20 mA
Input (Loop Break)
The loop break feature is associated with the 4-20 mA
input. Rate alarm relays may be programmed to go to
one of the following conditions when the controller
detects the loss of the input signal (i.e. < 0.005 mA):
1. Turn
On
(Go to alarm condition)
2. Turn
Off
(Go to non-alarm condition)
3. Ignore (Process as a low signal condition)
Note:
This is not a true loop break condition; if the signal
drops below 0.005 mA, it is interpreted as
a “loop break”
condition.
