Watson-Marlow 620DuN and 620Du User Manual 67
RS232 control
RS232 network control is available via a 9-pin D-connector wired as below.
RS232 is the mode which allows the pump to be controlled by computers and process
controllers. It can control every function of the pump, and pass data back to the con-
troller for closed loop operation. Up to 16 pumps can be individually controlled.
Recommended control cable: 7 strands 0.2mm, 24AWG, screened, circular, up to 4-
core. The cable screen should be earthed through the metalwork of the shell.
This pump passes all EMC compatibility requirements with up to 3m (10ft) of the
cable type specified above. Beyond this distance it is the user’s responsibility to
ensure the pump’s safe and reliable operation under remote and automatic control.
The 0V lines on this pump are mains transformer-isolated from ground (floating
ground).
Basic RS232 cabling
A pc can control one pump using
RS232 network cable 059.3121.000;
or more than one pump using additional RS232
network extension cables 059.3122.000, up to a
maximum of 16 pumps. If a connection must be made
to a pc fitted with a 25-pin serial outlet, use RS232 network adaptor 059.3123.000,
shown, dotted, left, instead of 059.3121.000.