Metrohm 731 Relay Box - Manual (Page 17)

2.4 Connections
Relay Box 731, Instructions for use 11
2.4.2 The Metrohm remote socket
Particular instrument functions can be triggered by activating the in-
dividual pins (connection pins) of a remote socket. The instrument
itself activates certain pins according to the instrument’s condition
and transmits signal pulses when particular events occur.
The functions which are used for remote control in an automated
system are allocated to logical remote lines. They are subdivided
into input lines (signal inputs to trigger functions, e. g. START or
STOP) and output lines (signal outputs to display the instrument’s
condition or events, e. g. 'ready' or 'End of Determination' =EOD).
The pin assignation of a 25-pin remote plug can be seen from the
information given below.
Output 6
Output 7
Output 4
Output 2
Output 0
Output 8
Output 9
Output 10
Input 1
Input 3
Input 5
Input 7
Output 11
0 Vo lt
+5 Volt
Output 5
Output 3
Output 1
Output 12
Output 13
Input 0
Input 2
Input 4
Input 6
0 Vo lt
Remote plug
(with 25 pins)
+5V
active = low
inactive = high
active = low
inactive = high
Inputs Inputs
Outputs Outputs
Electrical switching of the inputs
and outputs of the remote socket
Standard allocation of the remote lines in Metrohm instruments:
Remote lines Pin Function
Input 0 21 Start
Input 1 9 Stop
Input 2 22 Enter
Input 3 10 Clear
Input 4 23 Sample Ready
Input 5 11 not used
Input 6 24 not used
Input 7 12 not used
Output 0 5 Ready
Output 1 18 Conditioning ok
Output 2 4 Determination busy
Output 3 17 EOD (End of Determination)
Output 4 3 L1
Output 5 16 Error
Output 6 1 Activate L3
Output 7 2 Pulse for recorder
Output lines 8…13 are normally not used as standard.