1/29/2023 2:56 PM | |
Joined: 9/27/2006 Last visit: 9/21/2024 Posts: 12282 Rating: (2684) |
Hello goudarzi; The "Result of Logical Operation" is a part of the status word for logical instructions in Step 7, bit 1 It is used t keep track of the evolving status of all instuctions, as you can see in this document: http://www.plcdev.com/siemens_s7_status_word The RLO is set or cleared after each isntruction is evaluated with the RLO and other status word bits, as you can see from the screenshot below. The RLO is particularly important after a Jump or Call intruction, to initialize the following code you must make sure that the RLO is set to 1 for the logi to proceed, You can use the SET (set RLO to 1) or CLEAR (set RLO to 0) instructions in STL to manipulate the status of the RLO bit to ensure the logic works as you wanted to program it. Look at fritz' very clear desription on the subject in this discussion: https://support.industry.siemens.com/forum/ca/en/posts/set-and-clear/38369 Hope this helps, |
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1/30/2023 7:38 AM | |
Joined: 5/11/2022 Last visit: 8/26/2024 Posts: 62 Rating: (0) |
Hello sir Thanks for the information actually I need the real value of the RLO out of the Function.
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Last edited by: goudarzi91 at: 01/30/2023 07:39:22Last edited by: goudarzi91 at: 01/30/2023 07:39:38 |
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1/30/2023 10:28 AM | |
Joined: 3/30/2020 Last visit: 9/21/2024 Posts: 4777 Rating: (981) |
The instruction you are looking for is SAVE. This will influence the BR (bit result) that is made available on the ENO of the called block.
Also see the attached document. Do notice that it is a disadvantage to code in STL on an S7-1500. It is better to code in SCL if you wish to get faster processing. On the S7-300 / S7-400 the STL is best. AttachmentOverview of the EN or ENO mechanism in STL.pdf (237 Downloads) |
Last edited by: qwazee at: 01/30/2023 10:31:30Activities of this user is voluntary. There is no obligation or liability placed on this user. Though optional, your 'please' and 'thank you' is highly valued. |
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