Remote Connections; Digital Remote Control - Telemark Cryogenics 1200 Instruction Manual

2.8

Remote Connections

Telemark Cryochillers can be controlled remotely using digital connections
through a 37 way Amphenol socket, or Ethernet, RS 232 or RS 485 serial
communications. This section describes how to connect the unit remotely.
The unit is supplied as standard with Ethernet communication. RS 232 and
RS485 serial communications are optional.

2.8.1 Digital Remote Control.

The digital inputs are opto-isolated to provide galvanic isolation from
external source. Each input is also protected against RFI by the use
of filters that provide an additional protection against electrical noise.
The inputs rely on a positive voltage (+24VDC) to the input, reference
to isolated ground (ISO GND) for an action to take place. When the
signal is removed the Cryochiller will revert to its original state.
The digital outputs are via contact closures on relays. When a state is
"TRUE" then the contact will close. The outputs can be configured so
that the end user can either use the internal 24 VDC or use an
external voltage (indicate common) from the OEM equipment.
Telemark recommends that the OEM use an external voltage/ground
for the "indicate" common.
The Digital output signals are always re-sent irrespective if the unit is
in "Local" or "Remote" states.
The table below gives details of the 37 way connector pin functions
Telemark Cryogenics Microprocessor Based Cryochillers
Page 28 of 63
Revision 1.0.7 October 2018