Philips V24CT User's Reference Manual page 196

Realtime Wave Recordings
For central recorders, the requests are run and queued according to the
priority for that recorder. See the operating guide of the recorder for
information. For the M1116A/B Plug-In Recorder and the Philips M1117A
Bedside Recorder, the recording prints when the recorder is free.
Note—
Center (78504 and 78508) and you are using an 78572 recorder, please
observe the following rule:
6-24 Recording Functions
If you are using a monitor connected to a Patient Information
• Always select a valid waveform. Do not select "Blank" as the
waveform to be recorded in the Select Recording Waves Task
Window, as the recorder will not function. It will give the prompt
"Central recorder not available".
• For the Monitor connected to the a Philips central station, realtime
recordings must have at least one non-blank channel to generate a
recording on the central recorder.