Logic programming

The SLC 500 system is programed using the Rockwell Advanced Programming Software (APS$^{TM}$) which is installed on the PC that is located in the X1A sample preparation lab. The PC is only necessary for programming and/or trouble shooting since the software has been written to a EEPROM in the controller. The software uses Ladder Logic for programming. Ladder Logic is a graphical programming language based on electrical relay diagrams. Instead of having electrical rung continuity, ladder logic is looking for logical rung continuity. A ladder logic diagram identifies each of the elements in an electromechanical circuit and represents them graphically. Therefore, hardware components like relays and switches are replaced by the instructions Examine-If-Open (XIO, analogous to the normally open relay or switch contact), Examine-If-Closed (XIC, analogous to the normally closed relay or switch contact) and Output-Energize (OTE, analogous to the relay coil).

For more details on programming with the APS software, please refer to the APS user manual which can be found at the beamline.