USING PPP OVER A MODEM
SNAP PAC R-Series Controller User’s Guide
12
features that are not available in PAC Control. However, you cannot use the loopback
address in PAC Manager.
Choose your configuration tool based on what you need to do:
Whichever tool you use for configuring I/O, be aware of the impact if you later change
configuration. For example, if you configure I/O in PAC Manager, download the
configuration file to I/O units, and then later add a point in PAC Control, remember that your
configuration file doesn’t contain that point.
Using PPP Over a Modem
Use the rest of this chapter only if you have SNAP PAC R-series controllers installed at
remote locations or in other places where an Ethernet network is not available, and you are
using modems to communicate between the controller and a PC. The modems use the
point-to-point protocol (PPP) to communicate. You can set up communication so that the
controller can dial in to a PC, so that PCs can dial into the controller, or both.
NOTE: You can communicate with a SNAP PAC R-series controller using a modem and PPP at the
same time you are communicating with the controller over an Ethernet network.
Use PAC Control for I/O configuration if…
Use PAC Manager for I/O configuration if…
•
You have only one I/O unit or I/O unit configurations are
different.
•
The strategy will run on I/O units that are controlling
themselves using the loopback IP address (127.0.0.1).
•
You are using a wired Ethernet network for communications.
•
The strategy handles all logic; you are not also configuring
events and reactions on I/O units.
•
You have multiple I/O units whose configurations are exactly
the same or similar.
•
You are using a wireless LAN, a modem connection (PPP), or
SNMP.
•
You are using event messages or email.
•
You are configuring events and reactions on the I/O unit in
addition to strategy logic.
•
You are using OPC to communicate with I/O units.
•
You are not using PAC Control.
PC dials in to
controller
SNAP PAC R-series
controller
Modem
Modem
PC with dial-up
networking
Modem
