INSTRUMENT MANUAL
VACUUM GAUGE MODEL MM200
160Phone:(215) 947-2500 fax:(215) 947-7464 e-mail:[email protected] web site:www.televac.com
MM-200_im REV M
Page 83 of 160
TELEVAC
"GNx<cr>"
2. Assign a station to operate with Gas. Where "x" is the station to be switched to
have it's response calibrated for gas. This command is not allowed in the
"burst" mode. This command is different from assigning "Gas" from the front
panel in that it does not matter if the station is being displayed. In order for a
station to be selected for "Gas" operation by way of the front panel push
button, the station must be being displayed in the right hand display. The
response to this command is "A<cr>".
HOT CATHODE
"AH<cr>"
1. Go to the AUTO mode. The command causes the resident hot cathode gauge
to be controlled by the thermocouple or convection gauge that has the lowest
station number.
By control is meant, when the pressure of the controlling sensor exceeds 3
microns for uncoated tubes or 10 microns for coated tubes, the hot cathode
filament will shut off (as well as degas, had that been ON). The filament only
will come back on when the pressure of the controlling
ON.
"EH<cr>"
2. Go to the SELF-mode. This takes the hot cathode gauge out of the AUTO
mode or out of the OFF mode and allows it to shut itself down by virtue of it
reading a pressure above it's normal range. This command does not turn the
filament on. Initially or when the filament shuts down, it must be restarted
either through the front panel push button, or through the RS232 "FN<cr>"
command.
"EB<cr>"
3. Go to the "BOTH" mode. This enables the hot cathode gauge to be turned off
by either of the above events. When turned off by it's own reading being too
high, then it can only be turned on by operating the front panel set up
functions, or by way of the RS232 interface.
"FF<cr>"
4. Turn the hot cathode filament OFF. This command turns off the filament of the
hot cathode gauge. The filament cannot be turned on neither through the
front panel controls, nor through the control of it's associated thermocouple or
convection gauge.
"FN<cr>"
5. Turn the hot cathode filament ON. This command is like the front panel
selection of filament ready ("rdy"). If the HC gauge is in the "AUTO" mode,
the filament will go on if the pressure at the associated sensor is below the
turn off value, otherwise it will wait until the pressure is low enough.
"FNn<cr>"
6. Select filament #1 or #2. Where "n" is the filament number.