Metrohm 781 pH/Ion Meter: Operation via RS-232 - Manual (Page 28)

3.3 Pin assignment
26
780/781 pH/Ion Meter - Operation via RS232
Contact arrangement at plug (female) for RS232C socket (male)
Fig. 1: View of soldered side of plug
No liability whatsoever will be accepted for damage or injury caused by
improper interconnection of instruments.