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Siemens Logo digital input doesn't change state

Created by: mmatt111 at: 10/3/2018 1:31 PM (14 Replies)

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10/3/2018 1:31 PM	Rate (0)
mmatt111 Posts: 10 Rating: (0)	Hello, I have an issue with my Siemens Logo!8. I have connected it properly, and I can access it fine with the computer. It is a 12/24 VDC version to which I have connected a DC source on one of its digital inputs (I5). However, no matter what voltage I send to that I5 input, the I5 state remains at 0 when looking at the inputs/outputs monitor window (the one that refreshes every second). What am I doing wrong here? :(
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10/3/2018 2:08 PM	Rate (0)
NIBOU Bronze Member Joined: 10/20/2015 Last visit: 7/13/2024 Posts: 94 Rating: (19)	Hello mmatt111, Take a look at the attached photo. Is this the way that you wired the logo device? Attachment Connection Example.PNG (513 Downloads)

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10/3/2018 2:21 PM	Rate (0)
mmatt111 Posts: 10 Rating: (0)	Hello, Thank you for your quick answer. Please see attached how I've connected it. The "signal" output from my optical sensor is either 24V or 0V. Attachment unspecified.jpg (450 Downloads)
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10/3/2018 2:35 PM	Rate (0)
ixo65 Grandmaster Joined: 12/18/2014 Last visit: 9/3/2025 Posts: 35917 Rating: (4496)	mmatt111 The "signal" output from my optical sensor is either 24V or 0V. Please wrote us the data of the sensor (better a datasheet).

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10/3/2018 2:50 PM	Rate (0)
ixo65 Grandmaster Joined: 12/18/2014 Last visit: 9/3/2025 Posts: 35917 Rating: (4496)	Are the power supply of the LOGO! an d the sensor the same 24 VDC or different?

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10/3/2018 2:56 PM	Rate (0)
mmatt111 Posts: 10 Rating: (0)	The Siemens Logo uses the dedicated Siemens 24V DC power supply that is given with it, while the sensor uses a dedicated 24V DC power supply. Should the sensor 24V DC power supply and ground be connected instead to the Siemens power supply?
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10/3/2018 3:09 PM	Rate (0)
ixo65 Grandmaster Joined: 12/18/2014 Last visit: 9/3/2025 Posts: 35917 Rating: (4496)	Does not necessarily have to be. But the 0 V (or M) must be connected to each other so that the sensor and the LOGO! have the same potential. What kind is the output of the sensor? Relay? Or transistor? If transistor, PNP or NPN?

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10/3/2018 3:19 PM	Rate (0)
mmatt111 Posts: 10 Rating: (0)	Here is the datasheet of this sensor: Mine is a PNP-type output. Attachment e3z-ls_ds_e_9_2_csm436.pdf (470 Downloads)
mmatt111 Posts: 10 Rating: (0)	Last edited by: mmatt111 at: 10/3/2018 3:19:50 PM Last edited by: The Helping Hand at: 10/4/2018 11:21:44 AM Deleted link, added pdf.
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10/3/2018 3:29 PM	Rate (0)
ixo65 Grandmaster Joined: 12/18/2014 Last visit: 9/3/2025 Posts: 35917 Rating: (4496)	For sensors with transistor output, it may be that the input of the LOGO! the sensor is not enough load. Then you have to additionally wire a resistor. Attachment Resistor.zip (464 Downloads)

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This contribution was helpful to 1 thankful Users NIBOU

10/3/2018 3:51 PM	Rate (0)
NIBOU Bronze Member Joined: 10/20/2015 Last visit: 7/13/2024 Posts: 94 Rating: (19)	mmatt111 Here is the datasheet of this sensor: Mine is a PNP-type output. Sorry for the delay. See the attachment for PNP wiring. Attachment PNP.png (467 Downloads)
	Last edited by: The Helping Hand at: 10/4/2018 11:22:17 AM Deleted link from quoted text.
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