Endress+Hauser Topcal S CPC310, Руководство по эксплуатации

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Commissioning
88
7.6.14 Set up 2 - Limit switch
The transmitter has various methods of assigning a relay contact.
An on-value and off-value can be assigned to the limit switch as can a pick-up delay and drop-out
delay. Furthermore, if an alarm threshold is set an error message can also be output and a cleaning
function can be started in conjunction with this.
These functions can be used for both the primary value and for temperature measurement.
You can refer to the switching states in Fig. 59 to clearly understand the contact states of the relay.
• With increasing measured values (maximum function), the relay contact is closed as of t
2
when
the on value (t
1
) is exceeded and the pull-up delay (t
2
- t
1
) has elapsed.
The fault-signaling contact switches if the alarm threshold (t
3
) is reached and the alarm delay
(t
4
- t
3
) has also elapsed.
• When the measured values decrease, the fault-signaling contact is reset again when the alarm
threshold (t
5
) is undershot as is the relay contact (t
7
) later on after the drop-out delay (t
7
- t
6
).
• When the pick-up and drop-out delay are set to 0 s, the switch-on and switch-off points are also
switch points of the contacts.
In line with the maximum function, the same settings can also be made for a minimum function.
a0004352
Fig. 59: Illustration of the alarm value and limit value functions
A
B Switch-on point > switch-off point: Max. function
Switch-on point < switch-off point: Min. function 1
2
3
4
5
6
7 Alarm threshold
Switch-on point
Switch-off point
Contact ON
Alarm ON
Alarm OFF
Contact OFF