If the PLC has been created before and has had an arrangement stored in its memory, it will immediately begin working using the saved values. It will discover the earlier configuration parameters in its memory of system configuration and the earlier values of user logic in its user program memory if the PLC has a possible battery backup. Arrangement and user logic may be stored alternatively to the Flash RAM of PLC’s if you are not using a backup of battery.
The operating system ensures the configuration memory of PLC’s system first. It uses those values to run if it gets a valid configuration saved there. If it does not discover a valid configuration in the configuration memory system, it verifies the Flash RAM of PLC’s for a suitable configuration. If it gets a suitable configuration saved there, it utilizes those values to run. If the earlier condition of the PLC was in mode of RUN, the PLC will start scanning its logic directly. You do not require to connect a panel of programming to it. If the earlier condition of the PLC was in mode of STOPPED, you will need to attach a programming panel to one of the ports of Comm on the PLC sequentially to begin it.
Starting an Unconfigured PLC
If the system of operating cannot locate a suitable configuration in the system configuration memory or in its PLC’s Flash, it will turn on as an unconfigured device. A PLC will turn on unconfigured the first time it is ever been initiated or when its configuration values have been corrupted or cleared. You need to construct the PLC before you can service the I/O or write down a logic program.
Configuring a Modicon Micro PLC
Step 1. Link a panel turn on programming, for example MODSOFT Lite or the HHP*, to a comm port of RS-232 on the PLC.
Step 2. Using the system of panel’s menu, then go to the configuration editor.
Step 3. Ensure that the panel recognizes which type of PLC model (e.g. a 110CPU51200, a 110CPU31101,). The HHP* shows this information automatically at start up; MOD SOFT Lite on times you to choose the type of model from a list.
Step 4. Choose the preferred operating mode for the PLC you desire to construct. The operating mode can be either child, single, or parent.
Step 5. Move the parameters of configuration from the panel to the PLC.
Result. The panel constructs automatically the PLC with full valid parameters set according to the model and operating mode you identify.