The CPU board contains the microprocessor and RAM memory, a
real-time clock, LED indicators, INIT push button, and a
CompactFlash interface.
The base plate of the PM851A controller has two RJ45 Ethernet
ports (CN1, CN2) for connection to the Control Network, and two
RJ45 serial ports (COM3, COM4).
Note that a PM851/PM851A is restricted to one Ethernet
(CN1) port, thus redundant Ethernet is not available. One of
the serial ports (COM3) is an RS-232C port with modem control
signals, whereas the other port (COM4) is isolated and used for the
connection of a configuration tool.
Simple DIN rail attachment / detachment procedures, using the
unique slide & lock mechanism. All base plates are provided with a
unique Ethernet address which provides every CPU with a hardware
identity. The address can be found on the Ethernet address label
attached to the TP830 base plate.