Siemens ISOLATED MULTI-DROP SG-6048-01 - Manual (Page 9)

3
Installing the Converter
6 Siemens Energy & Automation, Inc.
3.4 Connecting with Short-Haul
Modems
If the distance between your PC and Isolated Multi-Drop
converter is greater than 50 feet but less than 3.5 miles, you
can connect them using short-haul modems and regular
telephone cable. To install the Isolated Multi-Drop converter
using short-haul modems, you need these items:
• two short-haul modems
• telephone cable that does not exceed 3.5 miles in
length
• one Isolated Multi-Drop converter mounting kit (if you
want to mount the converter in a switchgear panel)
• one or two RS-232 serial cables
for either side of the modem connection
For the RS-232 cables, use DCE-DTE cable with the pin
assignments given in Table 3.1. For mounting to a
switchgear panel, mount the converter before wiring. (Refer
to Appendix B for mounting dimensions.) Then follow these
steps, referring to Figure 3.3.
1. Connect short-haul modems to the RS-232 port on the
converter and to the RS-232 port on the PC. Plug them
directly into the ports or use the RS-232 serial cables.
(If you need help in connecting the modems and setting
their switches, refer to the modem’s manual.)
2. If you’re using application software that requires direct
DCD/RTS control, set the DCD/RTS switch to DCD
and the MAN/AUTO switch to MAN. If you are using
application software that does not require direct DCD/
RTS control, set the MAN/AUTO switch to AUTO, and
use the BAUD thumbwheel to set the data rate to
match that of the application software and the
ACCESS devices on the network. (In Automatic mode,
the converter ignores the setting of the DCD/RTS
switch.)
Figure 3.3 Connecting With Short-Haul Modems
+
+
+
+
SHLD
SHLD
SHLD
SHLD
-
-
-
-
Port 4
Port 3
Port 2
Port 1
+
+
-
-
Device
# n
Device
#1
PC
with
Supervisory
Software
RS-232 Cable
50 Ft. Maximum
Isolated Multi-Drop
Converter
To Other
RS-485
Devices
RS-485
Bus
22 AWG Shielded
Twisted-Pair Cable
4000 Ft. Maximum
Up to 32 devices
RS-232 Cable
50 Ft. Maximum
Short-
Haul
Modem
Short-
Haul
Modem
Two Twisted-Pair Cables
3.5 Miles Maximum
3. Insert the RS-485 connector(s) into the port(s) on the
front of the converter. (Refer to section 3.1 for
instructions on installing a connector on the RS-485
cable.)
4. Connect the supplied power cord to the 120 VAC
connection on the converter, and plug the other end
into any 120 VAC grounded power source.
5. Turn the converter’s power switch on, and verify that
the PWR LED is lit. (Refer to Section 5
“Troubleshooting” if the PWR LED is not lit.)
6. Start your software.