Metrohm 781 pH/Ion Meter: Operation via RS-232 - Manual (Page 23)

3 RS232 interface properties
780/781 pH/Ion Meter - Operation via RS232
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3 RS232 interface properties
3.1 Data transfer protocol
The pH/Ion Meter is configured as DTE (Data Terminal Equipment).
The RS232 interface has the following technical specifications:
• Data interface according to the RS232C standard, adjustable
transfer parameters, see page 16.
• Max. line length: 80 characters (incl. CR LF)
• Control characters: C
R
(ASCII DEC 13)
L
F
(ASCII DEC 10)
XON (ASCII DEC 17)
XOFF (ASCII DEC 19)
• Cable length: max. approx. 15 m
Start 7 or 8 Data Bit Parity Bit 1 or 2 Stop Bit
Only a shielded data cable (for example, Metrohm 6.2125.110 DB-
9/DB-25 or 6.2134.100 DB-9/DB-9) may be used to couple the pH/Ion
Meter with foreign devices. The cable shield must be properly grounded
on both instruments (pay attention to current loops; always ground in a
star-head formation). Only connectors with sufficient shielding may be
used