Metrohm 774 Oven Sample Processor - Manual (Página 134)

5 Descripción detallada
5.12 Properties of the RS232 Interface
5.12.1 Data Transfer Protocol
The 774 Oven Sample Processor is configured as DTE (Data Terminal
Equipment).
The RS232 interface has the folllowing technical specifications:
• Data interface according to the RS232C standard, adjustable transfer
parameters, see pages 86 and 143.
• Max. line length: 80 characters + C
R
L
F
• 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 changer with foreign devices. The cable shield must be
properly grounded on both instruments (pay attention to current loops; al-
ways ground in a star-head formation). Only plugs with sufficient shielding
may be used (for example, METROHM K.210.0001 with K.210.9004).
5.12.2 Handshake
Software-Handshake, SWchar
Handshake inputs on the changer (CTS, DSR, DCD) are not checked.
Handshake outputs (DTR, RTS) are set by the changer.
As soon as an L
F
is recognized the changer sends XOFF. After this it can
still receive and store 6 characters.
The changer also sends XOFF when its input buffer contains 60 characters.
After this it can receive 22 extra characters, (including L
F
).
If the transfer is interrupted for the time of 4 characters after the changer
has sent XOFF, the character string previously received will be processed
even if no L
F
has been sent.
774 Oven Sample Processor, Instrucciones para el uso 128