Gansu Ethernet module S7300

Gansu Liu Jiali 15929562304 Ethernet module S7-300 PLC user program when you want to keep in RAM, it will use the battery, the battery typically 3V or 3.6V non-rechargeable lithium battery, battery life is usually about five years , with a long battery voltage will drop, and when it drops to the RAM data is not sufficient to ensure, RAM in the program will be lost. If the user does not have a backup program that can be quite troublesome. General internal PLC has a battery voltage detection circuit, when the voltage drops to a certain extent, PLC will alarm, remind replace the battery. PLC's instruction manual has provided a method to replace the battery. In general, PLC after a power outage, because the PLC RAM power termination charging capacitors, even if the battery is removed, the capacitor charging power enough RAM data within a period of time, so after removing the battery in a short time if (usually 5 minutes) and then put a new battery to the data is not lost. But actually use the environmental conditions vary PLC, for example, the capacity of the capacitor drops, RAM power circuit dust, sludge and other form a discharge circuit, etc., which will speed up after the PLC power capacitors discharge rate, so that the time is not good grasp. If replacing the battery can be foolproof security procedures in the case charged. Because the power supply voltage is applied there will always be power pin RAM chips. Of course, also should be careful when replacing, note the battery polarity, and avoid short-circuits occur.