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make PLC retain the last value it read from the slave

Created by: tran_hau at: 8/2/2024 8:16 AM (2 Replies)

8/2/2024 8:16 AM	Rate (0)
tran_hau Joined: 8/2/2024 Last visit: 8/12/2024 Posts: 11 Rating: (0)	Thank you. Additionally, is there a way to make my PLC retain the last value it read from the slave? For example, if my slave sends a 1, Q1 will be turned on. However, if there is a power failure to the PLC and it loses power, after restoring power, will the PLC still remember the previous value of 1 and keep Q1 on? ------------------------------------------------------------------------------------------ Split from Support for Reading Modbus Slave and Controlling Output for PLC Logo.
	Last edited by: Moderator_Lan at: 08/05/2024 07:37:16 New subject after splitting
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8/2/2024 10:47 AM	Rate (1)
ixo65 Grandmaster-Expert Joined: 12/18/2014 Last visit: 11/12/2024 Posts: 34207 Rating: (4260)	Use a pulse relay. And set by the block properties the check mark by retentivity. A first pulse from V0.0 set the pulse relay, a second pulse from V0.0 reset the pulse relay.

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