Sensor Parameters - thyracont VSM77E Betriebsanleitung

5.7

Sensor Parameters

Sensor Transition (ST)
By default the VSM performs a continuous transition between Pirani and cold
cathode range whereupon an assimilation of the sensor signals is carried out.
In order to adapt the performance of the transducer to the requirements of the
vacuum process the following options can be configured via RS485 by means of
parameter "Sensor Transition" (ST):
"0": no transition, but direct switchover between Pirani and cold cath-
ode at 1.0 x10
"1": (Default) continuous transition in the range 1.0 ... 2.0x10
D[p]:* no transition, but direct switchover between Pirani and cold cath-
ode at pressure p
F[p1] T[p2]:* continuous transition in the pressure range p1 ... p2
Value range p, p1, p2: 4 x 10
*) Not accessible via EtherCAT
Cathode Control (CC)
For certain vacuum processes it may be favoured to suppress the automatic start
of the cold cathode sensor, which is usually controlled by the transducer elec-
tronics. Therefore it is possible to disable the cold cathode by software command
"Cathode Control" (CC) via RS485 interface:
disabled  cold cathode sensor remains switched-off
"0":
enabled  (Default) start of cold cathode is automatically controlled
"1":
When the cold cathode is disabled your VSM behaves like a Pirani transducer
with range 1000 - 1x10
-4
Below 1x10 mbar the serial interface sends a "ur" signal for underrange.
-3
mbar
... 2 x 10
-4
-4
mbar.
Parameter " Cathode Control" is only temporarily saved in the
transducer memory. After mains supply is switched off or dis-
connected the parameter will be reset to "1" and the cold cath-
ode enabled !
-3
mbar
39
-3
mbar
VSME-de-171111