Summary
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General Operation
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Suitable For
|
Ref. Number
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Sensor Validation
|
Produces a 4-20 mA output proportional to average of
two sensor inputs as long as both sensors are in bounds. If either
sensor goes out of bounds it is rejected and the output then becomes
proportional to the ‘good’ sensor. A relay contact is set to
annunciate the sensor failure which can be changed at the next scheduled
maintenance.
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MED2213
|
|
General pulse totalizer
|
PV is taken as a flow rate. Output 2, relay A is
pulsed for a user-configurable time when the integrated total reaches a
user-configurable value.
|
MED2113, MED2122, MED2133
|
|
Rate of change limiter
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Operates as a standard transmitters but limits the
maximum rate of change of the output to a user defined value.
|
MED2113
|
|
Peak/Valley Pick & Hold
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Provides a display an analog O/P proportional to
either the peak or valley input which is reset by an external digital.
The peak/valley also decays as a rate defined in TFML3.
|
MED2213
|
|
Pulse Totalizer
|
Takes 0-10V DC input equivalent to 0-400m3 hr and
provide 2 outputs. Output 1 4-20mA = 0-400m3 hr, output 2 relay 1 high
alarm, relay 2 pulse per total. For pulse output, relay ‘on’ time =
100ms.
|
MED2113
|
|
PI control – Relay Output
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This is the conventional PI control whereby a control
signal is derived which is proportional to the error and the integral of
the error. The output is sent to the proportioning relay output
The setpoint, P&I constants and the relay cycle time are entered via
TFNL registers.
Anti-windup is included i.e. the integral is reset to Zero whenever the
error is outside the proportional band.
|
MED2133
|
|
PID - 3 term control - continuous
|
This is the conventional PID control whereby a
control signal is derived which is proportional to the error, the
integral of the error and the derivative of the error. The setpoint and
PID constants are entered via TFNL registers.
Anti-windup is included i.e. the integral is reset to Zero whenever the
error is outside the proportional band.
|
MED2113
|
|
A-B
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Provides an analog output proportional to the
difference between the two inputs.
|
MED2211
|
|
A+B
or Average
|
Provides an output equal to the sum or average of
both inputs (or some other sub-multiple of the sum).
Both inputs are summed together and divided by TFML1, The output is then
scaled according to TFML2 and TFML3 and sent to the 4-20mA output.
|
MED2211, MED2213
|
|
Sample and Hold
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4-20mA output related to input, the digital input
initiates the hold, and the digital output is used as an alarm.
|
MED2113
|
|
High Input Selector
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This module takes two inputs and produces a 4-20 mA
output proportional to the highest of the two inputs.
Sensor A and B are set up in the normal way. The difference between the
highest is selected and output from Channel 1 as an analog signal, 4-20
mA ranges from TFML1 to TFML2.
Channel 2 output remains operational on channel 2 input as standard.
|
MED2213, MED2211
|
|
| NOTE: When using single
channel unit the TFML prompt will appear as tFnL on the unit display. |
