— 65 —
messaging requires a ‘straight-through,’ pin-for-pin DB9 exten-
sion cable, and a short one has been provided with the 730 En-
coder. Serial cable pinout is diagrammed in Figure 7A.
Modem Link
A modem link also may be used for addressing the encoder
from a remote location. When properly configured, a modem
link will appear ‘transparent,’ as if the encoder were connected
directly to the controlling computer or automation system.
Figure 7B shows proper pin connections for the cable used to
connect the 730 Encoder to a conventional external modem.
The three conductors shown are the only ones actually required
in this case.
Figure 7A
Figure 7B
Computer or Automation Cable
Modem Cable
STL Receiver
Cable
Figure 7C diagrams the
cable normally required
to interconnect the 730
Encoder with an STL re-
ceiver. Only three con-
nections are actually re-
quired for this RS-232 in-
terface, plus a pigtail
jumper in the end that
goes to the STL to fool
the receiver into a proper
‘handshake’ routine.
2 3
7
DB25 Male
(MODEM end)
2 3 5
DB9 Male
(ENCODER end)
(GND)
Figure 7C
STL Receiver Cable
DB9 Female
(COMPUTER or
AUTOMATION
end)
DB9 Male
(ENCODER end)
(GND)
1 2 3 4 5
6 7
8 9
DB9 Male
(STL RECEIVER end)
DB9 Male
(ENCODER end)
(GND)
(JUMPER)
1 2 3 4 5
6 7
8 9
1 2 3 4 5
6 7
8 9
