PAKBUS® features and the CR1000's capabilities

The following example discusses PAKBUS® features and the CR1000’s control ports communication capability. Without additional communication peripherals, it is possible to set up a small local network of CR1000s using the RS-232 serial port on one CR1000 and some 3-conductor cables. Let's say there are four CR1000s and the distance between any two hardwired CR1000s is less than 25 feet. The figure illustrates the network configuration and wiring. COM1 TX and RX are digital I/O
ports 1 and 2; COM2 TX and RX are digital I/O ports 3 and 4. The TX from one datalogger is connected to the RX at the other end and visa versa.

Before placing them in the network, the CR1000s are connected directly to the PC and configured with unique PAKBUS addresses (1, 2, 3, and 4 in the drawing) and with the appropriate COM ports set for PAKBUS communication. The CR1000s with addresses 1 and 3 are set up as Routers—to be able to pass on messages meant for another PAKBUS address. The Routers are also set to Beacon on the PAKBUS Ports—they send out beacons to locate other devices in the network. Thus, the PC running LoggerNet uses the RS-232 port of CR1000 #1 to communicate with any of the CR1000s in the network—to send programs, monitor measurements,
or collect data.