CHAPTER 2: QUICK START
SNAP PAC S-Series User’s Guide
17
NOTE: When connecting the controller to a managed switch, make sure the managed switch's port
configuration is set to Auto for the Duplex setting and Auto for the Speed setting.
Maximum cable or segment length is 100 meters; minimum cable length is one meter.
6.
If the controller will connect to I/O units on an RS-485 serial network, connect the serial cable following
the instructions in
“RS-232 and RS-485 Serial Networking”
below.
IMPORTANT:
Do not turn on power to the controller.
7.
Before
turning on power to the controller, follow steps in the
(form 1704) to
assign the controller an IP address. Note that you can use PAC Manager to assign IP addresses to the
controller and I/O units at the same time.
RS-232 AND RS-485 SERIAL NETWORKING
SNAP PAC S-series controllers provide both RS-232 and RS-485 serial communication interfaces. For serial
communication ports and their corresponding wiring pinouts, see
“Connectors, Indicators, and Pinouts” on
.
RS-232 Connections
You can use the RS-232 ports on a SNAP PAC S-series controller to:
•
Direct connect to a device that supports RS-232 communication.
•
Connect to a modem and make a serial Point-to-Point Protocol (PPP) connection to a remote PC or other
device that supports PPP.
Use PAC Manager to configure the RS-232 ports for the way you want to use them. (For instructions, see the
form 1704.) Note that the controller cannot make a direct RS-232 serial connection
with an Opto 22 I/O unit; however, it is possible to connect to an Opto 22 I/O unit that supports PPP
communications.
Attaching a Modem to the Controller
To work properly with the SNAP PAC S-series controller, a modem must be able to store settings in
non-volatile RAM (NVRAM) and default to those settings on reset.
IMPORTANT:
Any modem used with the controller must implement the Carrier Detect (CD) signal or use a custom
cable that connects CD to Data Terminal Ready (DTR).
1.
Connect the modem to the controller using a modem cable with female DB-9 connector. If necessary,
see
“Connectors, Indicators, and Pinouts” on page 21
for pinout details.
2.
Store configuration settings to the modem’s NVRAM, following instructions in the user’s guide for your
modem.
NOTE: Configuration settings
must
be stored to the modem’s NVRAM so they will be loaded when the controller
sends a reset command to the modem.
