3.4.1 GEM Pressure Logging Troubleshooting Page

The pressure reading from the Penning and Pirani gauges in the sample tank should be displayed on the dashboard, where they are called TPG3_A1 and TPG3_A2.

If the pressure readings are not displayed at all then type cset tpg3_a1/disp (and the same for tpg3_a2).

If the dashboard says "FALS" against either of the pressure readings then logging is off - it can be turned on by typing cset tpg3_a1/log, for example. By default, the pressure will be logged every 30 seconds, but a shorter update time, say 10 seconds, may be selected by typing cset tpg3_a2/log=10. Do not select an update time shorter than 10 seconds.

If the dashboard says "MOVE" against the pressure reading for a sustained period then it is likely that the connection has been broken. The current pressure readings may be read from the digital vacuum gauge readout which is located on the ground floor level, near the blockhouse door. The readout may be found in this location, above the PLC, as shown here.

A cable runs out of the back of the readout and should go into socket 23 on the patch panel next to the external shutter control box, here.

Another cable runs out of socket 23 on the patch panel in the GEM cabin, here, and goes into a CAMAC card in the GEM CAMAC crate, here.

It is possible to turn on & off the pressure gauges, using the digital display unit near the blockhouse door. This unit has a horizontal row of 4 black buttons. Press the leftmost button (button1) to select the selected vacuum gauge. Press buttons 1 & 2 simultaneously to turn off the selected vacuum gauge. Press buttons 1 & 3 simultaneously to turn on the selected vacuum gauge. 

Last updated on 22 Aug 2002 by Alex Hannon (a.c.hannon@rl.ac.uk)