Thermo Scientific Neslab Merlin M 75, Manual

Page: 83 / 107

Merlin 3 -1
Thermo Scientific
Chapter 3
Options
Communication
Connector
A female 9-pin D-connector is located on the rear of the chiller. The
connector is used for RS-232 serial communication (see Appendix B).
When the chiller is configured for serial communication the
LED on the controller is illuminated. If the chiller is shut off while still
configured for serial communication, the temperature display goes blank,
but the LED remains illuminated.
When the chiller is configured for serial communication it can be stopped
using the local controller. To restart, send another start command.
If the chiller
is
running and serial communications is enabled
( LED on), and you need to operate the chiller using the keypad – the
procedure is to press and hold for approximately two seconds until
the low temperature alarm icon illuminates. Press or , to scroll to
the
LED, press the down arrow and then press again to turn
communications off. The
LED will extinguish and the chiller can
now be operated from the keypad.
NOTE If serial communications is enabled, and the chiller is not running,
ensure the circuit protector is on and then simultaneously depress and
hold both the up and down arrow keys for approximately 10 seconds. The
display will show the temperature and the alarm, if enabled, will sound.
Then use the above procedure.

The pin out information is:
Pin
RS-232 COMM
1 No connection
2 TX
3 RX
4 No connection
5 GND = Signal ground
6 - 9 No connection
TX = Transmitted data from controller
RX = Received data to controller.
Hardware Mating Connector AMP Part# 745492-2 or equivalent