Metrohm 719 S Titrino - Manual (Page 99)

3.3 Properties of the RS 232 Interface
719 S Titrino
95
3.3 Properties of the RS 232 Interface
Data Transfer Protocol
The Titrino is configured as DTE (Data Terminal Equipment).
The RS 232 interface has the following technical specifications:
• Data interface according to the RS 232C standard, adjustable transfer pa-
rameters, see page 10.
• Max. line length: 512 characters
• 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 D.104.0201) may be
used to couple the Titrino 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 plugs with sufficient shielding may be
used (for example, METROHM K.210.0381 with K.210.9045).
3.3.1 Handshake
Software-Handshake, SWchar
Handshake inputs on the Titrino (CTS, DSR, DCD) are not checked.
Handshake outputs (DTR, RTS) are set by the Titrino.
As soon as a L
F
is recognized, the Titrino sends XOFF. It can then receive 6
extra characters and store them.
However, the Titrino also sends XOFF if its input buffer contains 60 charac-
ters. After this, it can receive maximum 22 extra characters (incl. L
F
).
If the transmission is interrupted for the time of 4 characters after the Titrino
has sent XOFF, the string received earlier is processed even if no L
F
has been
sent.