Endress+Hauser Mycom S CLM 153 Operating Instructions Manual page 66

6 Commissioning
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66
6.4.15 Set up 2 – Limit switch
The transmitter has several possibilities for assigning a relay contact. The limit contactor
can be assigned an on and off point, as well as a pickup and dropout delay. In addition,
an error message can be generated when an alarm threshold is set. You can trigger
cleaning in connection with this error message (see error/contact assignment page 45).
These functions can be used both for conductivity/concentration/resistance
measurement and for temperature measurement.
To illustrate the contact states of any relay contact or fault-signalling contact, refer to
fig. 25:
On-point > off-point (with increasing measured values):
– The relay contact closes after the on-point at t
(t - t ) expires.
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– When the alarm threshold at t
fault signalling contact switches.
– With returning measured values, the fault-signalling contact reopens when the alarm
threshold is undershot at t
– The relay contact opens again after the off-point is reached at t
has elapsed (t - t ).
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Note!
• If the pickup and dropout delays are set to 0 s, the on and off points are the switch
points of the contacts.
• You can make identical settings for a minimum function similar to the maximum
function.
Measured value
Alarm threshold
Contact ON
Switch-on point
Switch-off point
Switch-off point
Switch-on point
Fig. 25: Diagram of the relationship between on and off points and on and off delay
1
is reached and the alarm delay (t
3
. The appropriate error message is deleted.
5
Switch-on point > switch-off point:
Alarm ON
on
delay
Switch-on point < switch-off point:
Contact ON
Mycom S CLM 153
is exceeded and the pickup delay
- t ) also expires, the
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and the dropout delay
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Alarm OFF
Contact OFF
off
delay
Contact OFF
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