FAQs from Rohde & Schwarz

Modifications in R&S internal pump control


Description of modifications in the R&S internal pump control of liquid cooled transmitter family THx9 in software versions 20.0.2. and 21.0.0.


These modifications avoid unnecessary fault indications of the pumps in the transmitter logbook, optimize the regulation algorithm of the pumps and prevent deposits inside the pump bearings, which might cause pumps getting tight or even blocked in very rare cases.

1. Optimized cooling algorithm

  • Flow rate setting is optimized, now based on the lowest measured flow rate of both pumps instead of an average value.
  • The pump regulation cycles are modified, the overall flow rates are more constant.

2. Additional flushing cycles with adapted fault signalization

  • To prevent deposits inside the pump bearings, every 10 days the pumps are set for 3 minutes to 100% speed in order to flush the bearings and this way to remove possible deposits out of the pumps (this is a recommended procedure given by all main pump suppliers).
  • During this regular flushing cycle, all related cooling messages like “filter polluted”, logbook entries and status indications are suppressed.
  • When an internal “Pump Overload" status is detected for the very first time, it will also trigger the flushing cycle, during the flushing the “Pump Overload” status is suppressed.
  • If another pump „Pump Overload“ status is detected within 12 hours after the last flushing cycle, then this will be recorded in the logbook, the warning will be indicated via status-LED, via GUI and via SNMP and another flushing cycle will be triggered.