Rockwell Automation DAG6.5.8 APPLICATION GUIDE SCADA SYSTEM - Manual (Page 287)

Publication AG-UM008C-EN-P - February 2005
Configuring Modems 8-21
Table 8.20 MARC, Inc. Model 166-010 Pin Assignments
Switch Settings
The Model 166-010 (-xxx) modems have a set of four 16-position
rotary switches, S1 through S4, which are visible through an opening
in the side of the module cases. S1 is used to select the number of
rings to allow before answering a call. Setting S1 to zero will disable
the auto answer mode entirely. S2 is used to select the dialing mode
of the modem. Position 0 disables dial-out, position 1 enables dial-out
through one of two 24 VDC inputs wired to the module swing arm,
and position 2 enables ASCII string dialing using AT commands.
Switches S3 and S4 are only used on the Model 166-010-144 and -288
high speed modems. S3 sets the maximum modem connect baud rate,
and S4 selects the baud rate used to communicate with the PLC. (Note
that for the 2400 baud Model 166-010 modem, the maximum modem
connect baud rate is fixed at 2400 and the baud rate to communicate
with the PLC is fixed at 9600.) Setting both S3 and S4 to position 8 will
allow the high speed modem to connect at the maximum baud rate it
can negotiate with the remote modem, up to 14,400 or 28,800 baud,
and communicate with the PLC at 19,200 baud.
Radio Modem
Configurations Radio modems communicate over a radio frequency band. The FCC
requires that you obtain a license before you operate a radio modem
at a particular location and frequency within certain radio frequency
bands. Operating within a licensed radio frequency band minimizes
the chance of transmission interference from other nearby radio
modems. Unfortunately, in populated areas most, if not all, of the
radio frequencies are already licensed and in use.
The FCC allows you to use relatively low transmit power
spread-spectrum radio modems without a license. Spread-spectrum is
a transmission-frequency varying technique that lets many
spread-spectrum radios operate within the same radio frequency band
Modem
15-pin female
Pin Name Pin Name PLC-5
25-pin female
1785-KE
15-pin female
2 TXD.IN — TXD.OUT 2 2
3 RXD.OUT — RXD.IN 3 3
4 RTS.IN — RTS.OUT 4 4
5 CTS.OUT — CTS.IN 5 5
7 SIG.GND — SIG.GND 7 7
8 DCD.OUT — DCD.IN
8
(1)
8
(1)
11 DTR.IN — DTR.OUT 20 11
(1) Pin 8 is jumpered (within the connector) to pin 6.