96
SC-F70
SC-F70
PID Operation Operating Instructions
7.5 Sensor Problems
∑
When the measured values displayed are different from the actual sensor
reading, use this analysis and action.
* This section describes an example with a pressure transmitter
(MBS33M, from Danfoss A/S) and a temperatute sensor (TR1)
obtained from TLV. If you are using different equipment, contact
TLV.
Actions
Analysis
∑
Using pressure transmitter (MBS33M)
1. Confirm that the pressure is correct using a pressure
gauge.
2. Confirm that PG02 parameters are set as follows.
PVI
: 701
PVL : Lower limit of pressure sensor range
PVH : Upper limit of pressure sensor range
PVF : 0
PVb : 0
3. Measure the sensor signal at the back panel by
measuring the DC voltage between terminal 18
(
+
) and terminal 21 (
-
).
Measured
Voltage
(VDC)
5V
3
1
PVL
PVH
Intermediate
The secondary pressure value is proportional to the
measured voltage.
Lower Limit
1
Upper Limit
5
Intermediate
3
(PVH
-
PVL)
∏
2
Secondary
Pressure Value
∑
If the parameter setting is not
right, correct it.
∑
If the sensor signal is correct,
the controller should be
serviced. Contact TLV.
∑
If the measured voltage is over
5V, the pressure transmitter is
damaged. Replace it.
∑
For other cases, go to the next
step.
Current Input with
Power Supply
17
18
MBS33M
21
+
-
Sensor
4~20mA
(+)
(-)
DC Voltage Range
Note the polarity.