Thyracont VSH88D, Руководство по эксплуатации, Страница: 43 / 56

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vsh-de-130326
Degas-Control via RS485
Degas can also be controlled by corresponding software commands via RS485.
The degas procedure will stop automatically after approx. 3 minutes, but can be
cancelled any time by sending the corresponding software command.
While the sensor is degassing the red status LED is flashing slowly in red color.
Address Code Data cks CR
Address:
3 Bytes, decimal; address space RS485: 001 – 999
Code: "d" for writing the degas parameter
Data: 1 Byte; "1" for activating, "0" for deactivating degas
cks: 1 Byte, checksum, defined as sum over all Bytes of the fields
address, code and data, modulo 64 plus 64.
CR: Carriage Return (0Dh, 13d)
Example (for address-switch in position "1"):
Action Telegram to
transducer Answer telegram
from transducer
Activate degas
"001d1f
C
R
" "001d1f
C
R
"
Deactivate degas
"001d0e
C
R
" "001d0e
C
R
"
Read degas status
"001DU
C
R
" "001D1F
C
R
"
( Degas: on)
Please find further information about the Thyracont communication protocol in
chapter 4.2.
4.5 Readjustment
The transducer is adjusted ex works with 24V voltage supply in upright position,
flange to the bottom.
Other orientation, operation under different climatic conditions, extreme
temperature changes, ageing or contamination can result in the need for
readjustment of the Pirani sensor.
Readjustment by pushbutton
Readjustment on atmosphere or zero pressure can be done by means of the
ADJ pushbutton of the VSH (see operation scheme, chapter 4.3). The transducer
will notice automatically which adjustment point is relevant.
For zero adjustment actual pressure should be less than
5,0x10
-5
mbar.