Philips V24CT User's Reference Manual page 41

For most types of parameter modules, the system allows only one of each
type per patient (ECG, for example). Other types of modules allow more
than one per patient (Invasive Pressure, for example).
If too many modules or an unsupported module are plugged in, a message
detailing where the extra module is, appears in the system message field:
Currently ignored module in rack position R-P
where:
R is the number of the rack
(e.g. 1=integral rack, 2=first satellite rack,...
or 1=first satellite rack, 2=second satellite rack,...
P is the slot number in that rack
(counted from left to right)
The message
Unrecognized module in rack position R-P
is displayed if an unknown module is plugged into the rack.
Since the V24 and V26 Patient Monitors only support one module
Note—
rack, R will always be 1.
The CMS and V24 and V26 Patient Monitors 1-19
Parameter Modules