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| 11/27/2009 9:18 AM | |
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Posts: 23 Rating:
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Hello, I have a problem with old 313C CPU digital inputs (DI) modules states. The situation from the beginning is: 313C with its own I/O 3 modules x16 inputs 2 modules x16 outputs PLC firmware is 0.0 (about 2001 years) Now we added two modules: 32 DI and 32 DO after these 5 modules. The configuration is: 2. CPU 313C 3. IM365 4. DIx16 5. DIx16 6. DIx16 7. DOx16 8. DOx16 9. DIx32 10. DOx32 In the module of 32 DI, when I come online, i see only the first byte correctly as inputs are really TRUE or FALSE, but there is a problem with other inputs. Byte 2 is the "mirror" of module 5 (DIx16) second byte. Bytes 3 and 4 I dont see at all (I see them FALSES). When I disconnect the front connector of module 5 - the seconds byte inputs of module 9 also goes to FALSE. First of all I though maybe there is a problem with 32DI module. I tried the only 32DI near the CPU - all inputs i could see as they are. Then I changed the configuration - put 32DI near CPU 2. CPU 313C 3. IM365 4. DIx32 5. DIx16 6. DIx16 7. DIx16 8. DOx16 9. DOx16 10. DOx32 The problem now is: When i come online, second byte of module 7 is the "mirror" of second byte of module 6. When I disconnect the front connector of module 6 - the seconds byte inputs of module 7 also goes to FALSE. There is no address ovelapping in hardware configuration and this is not my first siemens plc, so there is no stupid mistakes. It is some anomaly.. I attached the online view of 32DI (when it was module 9) and module 5 (16DI) AttachmentDI_states.zip (403 Downloads) |
| 11/27/2009 10:15 PM | |
Joined: 5/28/2008 Last visit: 3/24/2025 Posts: 4520 Rating:
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Dear Arvydas, Please let us know if you are using more than one power supply in your system? If so, can you tell in if these two power supplies are comon ground or not or how did you connect them? Also let us know the part number of the twi DI modules you use (32 & 16) DI modules. And please check that you have connected the (M) of the power supply to (M) of each module you have selected. If you have more than one power supply, one of them feeds sensors or limit switches or whatever connected to one of these modules. check that the (M) of the DI module is connected to the (M) of the power supply which feeds the sensor or limit switch. Waiting for your feed back. Regards, |
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Ayman Elotaify |
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| 11/28/2009 10:06 AM | |
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Posts: 23 Rating:
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Dear Ayman, There is one power supply (5A). (M) of modules are connected to PS (M). Modules are: CPU: 313-5BE00-0AB0 (I was wrong writing about firmware 0.0. It is v1.0) 16DI: 321-1BH02-0AA0 32DI: 321-1BL00-0AA0. With connections there is ok. 24 VDC on module channel is, diode is lightning, but in online mode I don't see it. I see the "mirror" of previous module. If I disconnect the front connector of previous module, I don't see both modules - the disconnected one (it is normally, because I disconnected it), but also I don't see the next one module inputs (which has 24 VDC at input, diode is lightning). Arvydas |
| 11/28/2009 11:09 AM | |
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Joined: 5/28/2008 Last visit: 3/24/2025 Posts: 4520 Rating:
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Dear Arvydas, For module 16DI: 321-1BH02-0AA0, (M) of the power supply should connected to pin 20 For module 32DI: 321-1BL00-0AA0, (M) of the power supply should connected to pins 20 & 40.
The above statment is not clear to me. Can you please explain it in more details? Also, Did you checked that there's no bridge connection between modules and each other. Short circuit between channels may be the reason of your problem and it may be comes from the field side. You can make simple excersise. Disconnect all sensors from all DI modules. Only (M) connections for these modules is needed. Then apply 24 voltage to each channel of each DI module using a wire. Then see if the "mirror"effectis still happen or not. Waiting for the result. Regards, |
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Ayman Elotaify |
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| 11/28/2009 1:32 PM | |
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Posts: 23 Rating:
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Dear Ayman, There is no short circuit between channels. I think this is a problem how CPU reads the I/Os. As I wrote in first post in the beginning it was a problem with one module, after changing configuration - with another module. First of all there was configuration in project: 2. CPU 313C 3. IM365 4. DIx16 5. DIx16 6. DIx16 7. DOx16 8. DOx16 Now we added two more modules: 2. CPU 313C 3. IM365 4. DIx16 5. DIx16 6. DIx16 7. DOx16 8. DOx16 9. DIx32 10. DOx32 In online mode I see correctly only first byte of module 9 (32DI). Second byte of module 9 in online mode has the "mirror" effect of module 5 (16DI) second byte. Then the another 2 bytes in online mode are FALSES. But in really some of them should be visible as TRUE (24VDC is, Input diode is ON). If I disconnect the front connector of module 5 (but not module 9), in online mode seconds bytes inputs of module 9 goes OFF (because they are somehow "mirrored" from module 5). I tried the only 32DI near the CPU - all inputs i could see as they are. Then I changed the configuration - put 32DI near CPU 2. CPU 313C 3. IM365 4. DIx32 5. DIx16 6. DIx16 7. DIx16 8. DOx16 9. DOx16 10. DOx32 The problem now is the same, only mirror effect is on module 7 second byte from module 6 second byte. As You said: "You can make simple excersise. Disconnect all sensors from all DI modules. Only (M) connections for these modules is needed. Then apply 24 voltage to each channel of each DI module using a wire. Then see if the "mirror"effectis still happen or not." Yes, we tried this in a very beginning when this problem occured, there is mirror effect and I don't know the reason. Our local "siemens" says, they hear such a problem for the first time. I see it also for the first time, because normally there is no problem with I/O reading. Arvydas |
| 11/28/2009 10:11 PM | |
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Joined: 5/28/2008 Last visit: 3/24/2025 Posts: 4520 Rating:
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Dear Arvydas, Really strange problem! May be something wrong in the modules. Let's try another thing. What will happen if you put only two modules in slots 4 & 5. And do not connect the field to DI channels. Only (M) to the modules should be connected. Then try each DI channel and see what will happen. Then disconnect the front connectors and install other two modules and so on.
How did you know that the DI should be true? You said diod is On. Did you meant the led of the DI channel is lit and it is False in Variable table? If so, Please measur the Voltage on this channel using a multmeter. If the voltage is lower than 13VDC, The led is lightlly lit but the DI is False. Please see the attached picture from the manual. Regards, |
Last edited by: Ayman Elotaify at: 11/28/2009 10:22 PMAyman Elotaify |
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| 11/29/2009 11:52 AM | |
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Posts: 23 Rating:
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Dear Ayman, Yes I measured voltage, it was about 24VDC, channel diode was ON, but in variable table I saw FALSE. Tomorrow I will be in a plant again, and there will be a possibility to make a test as You said with two modules in slots 4 and 5. Regards, Arvydas |
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