A beginner is asking how to read this logic; I’m completely confused.
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The logic is as above. If you understand, just say so. Please explain it as clearly as possible..... Thank you
There’s nothing special about this. In the first line, when the start signal is sent, TON represents a delay before activation; in other words, if no operation signal is received within a certain time after the start signal is sent, and no reset is performed, a fault is reported. In the second line, the fault is reset
The third and fourth rows represent the start signal; R_trig is used for rising-edge detection, and when a rising-edge signal appears, it triggers a set operation thereafter
This post was last edited by 氵巟丶氵少 on May 26, 2018, at 16:01. Starting from the first line: the pump is activated; the normally open contact of P601 closes, sending a signal to the TON timer. Different timers have different time delay units as a reference; these can be looked up. Multiply that value by 2000. For example, after 20 seconds, check whether the pump is operating normally. If it is functioning properly, the normally closed contact of ZP601 opens, thereby interrupting the signal. If the pump fails to operate normally, the normally closed contact of ZP601 remains closed. Connected to this is a normally closed contact of a reset button, which serves to cut off the alarm signal—see the second line. Pressing the reset button causes the normally open contact of FW ALM to close, thereby resetting the alarm. Meanwhile, the normally closed contact of FW ALM in the first line opens, thus cutting off the alarm signal. The third and fourth rows contain the normally open contacts for the screen start switch and the on-site start button; when these contacts are closed, a rising edge is generated, which is captured by the subsequent flip-flop. The signal is then sent to the subsequent OR gate OR BOOL, thereby enabling the pump – in other words, pressing either of these buttons will start the pump. Lines 5, 6, and 7 describe the procedure for stopping the pump; any trigger will cause the pump to be reset. Line 5 involves resetting the pump in case of an alarm. Line 6 shows ND P601, which is a switch for controlling the pump’s operation – it is not a button. It shares the same contact as ND P601 on line 3. When the pump is running, this contact remains closed. The triggers connected to these two contacts detect either an upward edge or a downward edge in the signal: when the switch is turned on, R TRIG detects the upward edge and starts the pump; when the switch is turned off, F TRIG detects the downward edge and stops the pump. Line 7 refers to the on-site button for stopping the pump – when the button is pressed, the normally closed contact opens, and when the button is released, the normally closed contact closes, thereby creating an upward edge in the signal. In other words, the pump stops when the button is released after it has been pressed.
I can’t read the first paragraph. P601 is activated, which causes P601 to close. After 20 seconds, why does ZP601 disconnect, does FW601 disconnect as well, and then does FP601 give an alarm?
On the first line, after the pump starts, if there is no signal indicating that it is in operation for a certain number of seconds, then a fault is reported. If the logic used to determine operation is based on a normally open circuit, then it’s incorrect; since there is already a signal indicating operation, why is a fault still reported?
This is a logic for determining the operation signal; after it is activated, a 2000 MS delay is applied, and if the operation signal is normal, no alarm is issued； Conversely, an alarm is issued when FW_ALM is not triggered, which in turn activates F_P_601 and causes the pump to stop. For these three, it might be easier to understand if you look at them in the order of 2--3--1