Pc Requirements; Modem Requirements - GE KVGC 202 Technical Manual

KVCG202/EN M/H11
7.3.4

PC requirements

To operate fully, the above programs require:
IBM PC/XT/AT/PS2 or true compatible
-
- 640 kBytes of main memory RAM
- Graphics adapter CGA, EGA, VGA or MDA
Serial adapter port configured as COM1 or COM2 (RS232)
-
Floppy disc drive 3.5 inch
-
MS-DOS 3.2 or later/IBM PC-DOS 3.2 or later
-
Parallel printer port for optional printer
-
- Additional equipment
- Printer
RS-232 link
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KITZ 101/KITZ 102/KITZ 201 K-Bus/RS232 communication interface
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Modem
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7.3.5

Modem requirements

Alstom Grid have adopted the IEC 60870-5 ft1.2 frame format for transmitting the courier
communication language over RS-232 based systems, which includes transmission over
modems.
The IEC 60870-5 ft1.2 specification calls for an 11-bit frame format consisting of 1 start
bit, 8 data bits, 1 even parity bit and 1 stop bit` However, most modems cannot support
this 11-bit frame format, so a relaxed 10-bit frame format is supported by the Protection
Access Software & Toolkit and by the KITZ, consisting of 1 start bit 8 data bits, no parity
and 1 stop bit.
Although Courier and IEC-870 both have inherent error detection, the parity checking on
each individual character in the 11-bit frame provides additional security and is a
requirement of IEC 60870 to meet the error rate levels it guarantees. It is therefore
recommended that modems should be used which support these 11-bit frames.
The following modems have been evaluated for use with the full IEC 60870 ft1.2 protocol
and are recommended for use:
Dowty Quattro (SB2422)
Motorola Codex 3265 or 3265 Fast
Other modems may be used provided that the following features are available; refer to
the modem documentation for details on setting these features:
Support an 11 bit frame (1 start bit, 8 data bits, 1 even parity bit and 1 stop bit). This
feature is not required if the 10-bit frame format is chosen.
Facility to disable all error correction, data compression, speed buffering or automatic
speed changes.
It must be possible to save all the settings required to achieve a connection in non-
volatile memory. This feature is only required for modems at the outstation end of the
link.
Notes: 1. The V23 asymmetric data rate (1200/75bps) is not supported
2. Modems made by Hayes do not support 11 bit characters.
Technical Manual
KVGC202