Fresenius Medical Care 4008 E Technical Manual page 319

Raising the level in the venous bubble catcher
The H level at pin 1 of X351 is inverted by IC 18, pins 3 and 6; or the L level at pin 3 of X154
energizes FET T16 via IC 15, pins 5, 6, 4. The vent valve is opened by FET T16. Simultaneously,
the LEV-UP-OUT signal is inverted via IC 15, pins 8, 9, 10. The venous line clamp is blocked via
DI17, and level raising is blocked at IC 15, pin 12.
Lowering the level in the venous bubble catcher
An L level at X154, pin 1, energizes FET T15 via IC 18, pins 2, 9. FET T15 activates the ventilation
pump and, in addition, the vent valve via DI16. Level lowering can be blocked via an H level
applied to pin 1 or pin 8 of IC 18. This is the case, if an L level is applied to at least one of pins 1,
2, 12, 13 of IC 15 (in case of a level detector alarm from channel 1 or 2; if the venous line clamp
is being closed by external control; or in case of LEV-UP).
8-22
Fresenius Medical Care 4008 4/09.03 (TM)