HEIDENHAIN TNC 407 (243 020) Service Manual - Manual (Page 67)

SERVICE MANUAL TNC
Issue:
01.09.19958
Page 56
14.3 Connecting Cables and Adaptors for the RS 232C Interface
14.3.1 Wiring Diagram and Adaptor of the RS 232C Interface
Cable RS232 LE 232 Adaptor Block
LE 239 760 239 758 01
Signal Designations:
Transmit Data
RXD Receive Data
RTS Request to Send
CTS Clear to Send
DSR Data Set Ready
DTR Terminal Ready
Data Transfer Cable
242 869 01
FE
ME 101
In general simplified wiring of the
data transfer cable is sufficient
for the transfer via the RS 232C
interface with protocol.
The data lines and the control lines of the cable between the LE and the RS 232C adaptor block
239 760 are transposed. The pin layout at the connector X21 of the LE corresponds that
of a data circuit terminating equipment Due to the transposed data lines and control lines in the cable
between the LE and the RS 232C adaptor the allocation at the RS 232C adaptor corresponds to a
data terminal equipment Thus, the external units may be connected to the RS 232C adaptor via the
standard data transfer cable 242 869
The RS 232C data interface has different pin assignments at the logic unit X21 and at the
RS 232C adaptor block.