Chapter 6 ______________________________________________________________ Maintenance
VAISALA ______________________________________________________________________ 205
If the optional modem DMX501 needs to be replaced, the instructions for
replacing the master CPU LTC212 should be followed. If the LTC212 is
removed from the interface unit, the replacement modem can simply be
plugged on the master CPU as shown in Figure 119 below.
NOTE
Pay attention to the correct position of the connectors and the orientation
of the module.
0401-158
Figure 119 LTC212 with Optional Modem DMX501
Pay attention to the handling notes given above for the master CPU
LTC212.
Carry out the re-assembling like described for LTC212 above.
Replacing Receiver Measurement Unit
LTM212
To replace the complete receiver measurement unit, the AC power has to
be switched off first and then the measurement head cover has to be
removed.
1.
Remove the upper interface unit cover and open the interface unit
with the provided key.
NOTE
Switch the AC switch off, before you proceed with the next steps. In
case of the optional LTBB111, switch the battery backup switch off as
well. See Figure 40 on page 83.
2.
Loosen the three lock screws at each side of the measurement head
cover and carefully remove the cover from the measurement head.
See Figure 95 on page 140.
3.
The measurement unit is fixed with two fastening screws. Through
the mast adapter of the support unit, these two hex-socket screws,
size 4 can be reached. See Figure 78 on page 118.