The programmable controller of PLC-2/30 contains of:
• The processor of 1772-LP3
• A structure of I/O is I/O chassis which containing I/O modules.
The processor of 1772-LP3 has a CMOS memory of read/write that saves the instructions of user program, I/O device and numeric values status. The user program is an instructions set in a particular order that explains the operations to be carried out and the running conditions. It is filled into memory, rung by rung, in a functional block display format and ladder diagram from the 1784–T50 or 1770-T3 terminal keyboard. The symbols of ladder diagram directly resemble the symbols of relay used in control systems of hardwired relay. The functional block shows are an simple method of programming and advanced instructions monitoring.
The processor of PLC-2/30 constantly monitors the input devices status during program operation, based on user program instructions, either output devices of energizes or de–energizes. The user program can be eagerly changed if needed by the application because the memory is programmable.
The functions of PLC-2/30 processor comprise:
• Functions of timing: Off-Delay and On-Delay, Retentive and Non-retentive with timing range 0.02 to 999 seconds.
• Up or down bidirectional counting from 0 to 999 counts.
• Diagnostic capabilities and self-monitoring
• The data table is expandable
• The capacity of memory is 16,256 words
• comprehensive forced I/O
• Data comparison
• Data transfer
• 3-digit, 4-function arithmetic (+, –, ×, :–) :–:–
• The capacity of 896 I/O device is existing in local or remote configurations.
• When used with specific configurations it consists 896 inputs and 896 outputs.
• Memory write protect
• The instructions of program control
- Subroutines
- Jump
• Instructions of Functional Block
- Instructions of Shift Register
- Logic instructions of Word-to-File and File-to-File
- Transfer instructions File-to-Word, Word-to-File and File-to-File
• Conversions BCD to Binary and Binary to BCD
• Programming online
• Compatible to Data Highway and Data Highway II
• Report generation
• Contact histogram
• Sequencers
You can increase the data table from 128 words or 1 rack (the default size) to 256 words or 2 racks of word address 3778 in two-word increments. The data table has to be increased in 128-word sections from word address 4008 on. Therefore, The I/O image tables can be arranged in size from 1 to 7 racks of I/O. Each rack added increases by 108 the first existing address for counters and timers.