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Milltronics SF 500 - INSTRUCTION MANUAL
7ML19985CN01
mmmm
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Opear
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control, output 2 is assigned to PID control loop 1 and output 3 is assigned to PID control
loop 2.
Input
The optional mA I/O board provides two mA inputs, programmable as inputs 1 and 2. If
programmed for PID control, assign input 1 to PID control loop 1 and input 2 to PID control
loop 2.
The input range can be set to 0-20 mA or 4-20 mA (P250), and assigned a function (P255),
e.g. PID setpoint. The 4 and 20 mA levels can be trimmed (P261 and P262) to agree with an
external device.
Relay Output
The SF 500 offers five single pole single throw (SPST) relays that can be assigned (P100)
to one of the following alarm functions:
•
rate:
relay alarms on high and/or low material flow rate.
•
diagnostic:
relay alarms on any error condition as it is reported.
Refer to
Troubleshooting
on page 118.
•
PID:
PID control setpoint deviation*
•
batch pre-warn
•
batch setpoint
*is offered only if the PID system (P400) is enabled.
For rate alarm functions, enter the high and low alarm setpoints (P101 and P102
respectively) in the appropriate units. The high alarm setpoint acts as the setpoint
deviation alarm for relays programmed for PID setpoint deviation.
The on/off actuation at both high and low setpoints is buffered by the damping (P080) and
the programmable dead band (P117), to prevent relay chatter due to fluctuations. The
relay is normally energized; holding the normally open (n.o.) contact closed (can be
programmed for reverse operation, P118). In an alarm condition, the relay is de-energized
and the relay contact is opened. Once in alarm, the relay remains in alarm state until the
alarm condition is removed.
Example:
P011 = 360 t/h
P100 = 1-rate
P101 = 100% (360 t/h)
P102 = 20% (72 t/h)
P117 = 2% (7.2 t/h)
Alarm is ON with relay de-energized.
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