Areva KITZ 101, User Manual

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Page 17
4.1 RS232 (IEC-870) connection
4.1.1 Recommended cable
A standard PC serial port interface cable (with the connections listed in Table 1)
should be used. It is essential that the cable screen is earthed at one end to
ensure adequate screening. The connectors should be screw-locked to the KITZ
and the PC.
4.1.2 Cable length
The maximum recommended length of cable from the IEC-870 Communications
port is 15 metres (50 feet) or 2500 pF total cable capacitance. For longer
distance communication on the IEC-870 port an external RS485 interface may
be required.
4.1.3 Data rates
The maximum data communication rate specified in the RS232-c standard is
20 kbits/s. The KITZ unit will support faster communication data rates (up to
115.2 kbits/s) for use with development tools such as K-Spy.
The following table shows the connections required to interface a KITZ to a user
PC serial data port. These connections are for guidance only and reference
should be made to the PC user manual.
Note that the terms “Receive Data” and “Transmit Data” (in Tables 1 and 2)
refer to the named connector and not to a nominated end.
KITZ PC-at laptop PC or PS/2 Type
25 Pin ‘D’ male 9 Pin ‘D’ male 25 Pin ‘D’ male
connector (DTE) connector (DTE) connector (DTE)
1 – Protective Ground No Connection 1 – Protective Ground
See note
2 – Transmit Data 2 – Receive Data 3 – Receive Data
3 – Receive Data 3 – Transmit Data 2 – Transmit Data
7 – Signal Common 5 – Signal Common 7 – Signal Common
Connector Shell to
Cable Screen (see note)
Table 1 KITZ/PC RS232 port inter-connections.
Note: The RS232 cable screen should be connected to earth at one end only,
to prevent earth loops.
Pin 7 (Signal Common) or Pin 1 (Protective Ground) can be used as
an alternative to the Connector Shell.