Can 2 devices plugged in obd port cause problem?












1















I'm newbye in this area, so I apologize in advance if I will ask something stupid.
Shortly, I'm writing a software on top of connected cars that means that we are going to decorate and package data coming from an OBD_2 dongle.



Now, we are testing our product on a new Mercedes with connect.me service already installed. This service gets data throw another dongle plugged to the obd port (in the dashboard).



So in our case, the car has 2 dongles reading data from obd port.



The problem is that when we plug our device in,the dashboard shows an error message saying something like "limited me.connect service"



What are the reasons of this conflict? How can a read only device cause problem to another?



I'm sure I didn't use the right words but the point is how ro devices can cause problems each other.










share|improve this question







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Check out our Code of Conduct.
















  • 1





    Welcome to Motor Vehicle Maintenance & Repair! Realistically to me, you should be able to do this without conflict. I mean, the OBD2 system runs over a CAN Bus with many different computers vying for time on the Bus. As long as you are requesting information correctly through the bus, I'd think you shouldn't have an issue. I'd suspect your "reader" is trying to take over instead of just reading. I'm no expert, so this is just conjecture ... leaving it as a comment.

    – Pᴀᴜʟsᴛᴇʀ2
    7 hours ago













  • Thank you @Pᴀᴜʟsᴛᴇʀ2. What do you mean with "...trying to take over..."?

    – Luca Rasconi
    6 hours ago











  • How are the two devices connected? As Mike and JPhi1618 have said, there's usually only one port. If you've added some kind of adaptor to allow two devices to connect to one port, this might not be passing all the manufacturer-specific pins correctly?

    – Nick C
    5 hours ago











  • @LucaRasconi - Obviously there's a conflict with what you're putting on your CANBus and what already exists on the system. I'm suggesting whatever your putting on there is overriding the me.connect. I'm not quite sure what you mean by "decorate and package" data. Would it in any way be better for the car system to send/receive data through the me.connect system instead of interrogating the OBD2 system directly?

    – Pᴀᴜʟsᴛᴇʀ2
    4 hours ago
















1















I'm newbye in this area, so I apologize in advance if I will ask something stupid.
Shortly, I'm writing a software on top of connected cars that means that we are going to decorate and package data coming from an OBD_2 dongle.



Now, we are testing our product on a new Mercedes with connect.me service already installed. This service gets data throw another dongle plugged to the obd port (in the dashboard).



So in our case, the car has 2 dongles reading data from obd port.



The problem is that when we plug our device in,the dashboard shows an error message saying something like "limited me.connect service"



What are the reasons of this conflict? How can a read only device cause problem to another?



I'm sure I didn't use the right words but the point is how ro devices can cause problems each other.










share|improve this question







New contributor




Luca Rasconi is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
















  • 1





    Welcome to Motor Vehicle Maintenance & Repair! Realistically to me, you should be able to do this without conflict. I mean, the OBD2 system runs over a CAN Bus with many different computers vying for time on the Bus. As long as you are requesting information correctly through the bus, I'd think you shouldn't have an issue. I'd suspect your "reader" is trying to take over instead of just reading. I'm no expert, so this is just conjecture ... leaving it as a comment.

    – Pᴀᴜʟsᴛᴇʀ2
    7 hours ago













  • Thank you @Pᴀᴜʟsᴛᴇʀ2. What do you mean with "...trying to take over..."?

    – Luca Rasconi
    6 hours ago











  • How are the two devices connected? As Mike and JPhi1618 have said, there's usually only one port. If you've added some kind of adaptor to allow two devices to connect to one port, this might not be passing all the manufacturer-specific pins correctly?

    – Nick C
    5 hours ago











  • @LucaRasconi - Obviously there's a conflict with what you're putting on your CANBus and what already exists on the system. I'm suggesting whatever your putting on there is overriding the me.connect. I'm not quite sure what you mean by "decorate and package" data. Would it in any way be better for the car system to send/receive data through the me.connect system instead of interrogating the OBD2 system directly?

    – Pᴀᴜʟsᴛᴇʀ2
    4 hours ago














1












1








1








I'm newbye in this area, so I apologize in advance if I will ask something stupid.
Shortly, I'm writing a software on top of connected cars that means that we are going to decorate and package data coming from an OBD_2 dongle.



Now, we are testing our product on a new Mercedes with connect.me service already installed. This service gets data throw another dongle plugged to the obd port (in the dashboard).



So in our case, the car has 2 dongles reading data from obd port.



The problem is that when we plug our device in,the dashboard shows an error message saying something like "limited me.connect service"



What are the reasons of this conflict? How can a read only device cause problem to another?



I'm sure I didn't use the right words but the point is how ro devices can cause problems each other.










share|improve this question







New contributor




Luca Rasconi is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.












I'm newbye in this area, so I apologize in advance if I will ask something stupid.
Shortly, I'm writing a software on top of connected cars that means that we are going to decorate and package data coming from an OBD_2 dongle.



Now, we are testing our product on a new Mercedes with connect.me service already installed. This service gets data throw another dongle plugged to the obd port (in the dashboard).



So in our case, the car has 2 dongles reading data from obd port.



The problem is that when we plug our device in,the dashboard shows an error message saying something like "limited me.connect service"



What are the reasons of this conflict? How can a read only device cause problem to another?



I'm sure I didn't use the right words but the point is how ro devices can cause problems each other.







obd-ii






share|improve this question







New contributor




Luca Rasconi is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











share|improve this question







New contributor




Luca Rasconi is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









share|improve this question




share|improve this question






New contributor




Luca Rasconi is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.









asked 7 hours ago









Luca RasconiLuca Rasconi

1063




1063




New contributor




Luca Rasconi is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.





New contributor





Luca Rasconi is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






Luca Rasconi is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.








  • 1





    Welcome to Motor Vehicle Maintenance & Repair! Realistically to me, you should be able to do this without conflict. I mean, the OBD2 system runs over a CAN Bus with many different computers vying for time on the Bus. As long as you are requesting information correctly through the bus, I'd think you shouldn't have an issue. I'd suspect your "reader" is trying to take over instead of just reading. I'm no expert, so this is just conjecture ... leaving it as a comment.

    – Pᴀᴜʟsᴛᴇʀ2
    7 hours ago













  • Thank you @Pᴀᴜʟsᴛᴇʀ2. What do you mean with "...trying to take over..."?

    – Luca Rasconi
    6 hours ago











  • How are the two devices connected? As Mike and JPhi1618 have said, there's usually only one port. If you've added some kind of adaptor to allow two devices to connect to one port, this might not be passing all the manufacturer-specific pins correctly?

    – Nick C
    5 hours ago











  • @LucaRasconi - Obviously there's a conflict with what you're putting on your CANBus and what already exists on the system. I'm suggesting whatever your putting on there is overriding the me.connect. I'm not quite sure what you mean by "decorate and package" data. Would it in any way be better for the car system to send/receive data through the me.connect system instead of interrogating the OBD2 system directly?

    – Pᴀᴜʟsᴛᴇʀ2
    4 hours ago














  • 1





    Welcome to Motor Vehicle Maintenance & Repair! Realistically to me, you should be able to do this without conflict. I mean, the OBD2 system runs over a CAN Bus with many different computers vying for time on the Bus. As long as you are requesting information correctly through the bus, I'd think you shouldn't have an issue. I'd suspect your "reader" is trying to take over instead of just reading. I'm no expert, so this is just conjecture ... leaving it as a comment.

    – Pᴀᴜʟsᴛᴇʀ2
    7 hours ago













  • Thank you @Pᴀᴜʟsᴛᴇʀ2. What do you mean with "...trying to take over..."?

    – Luca Rasconi
    6 hours ago











  • How are the two devices connected? As Mike and JPhi1618 have said, there's usually only one port. If you've added some kind of adaptor to allow two devices to connect to one port, this might not be passing all the manufacturer-specific pins correctly?

    – Nick C
    5 hours ago











  • @LucaRasconi - Obviously there's a conflict with what you're putting on your CANBus and what already exists on the system. I'm suggesting whatever your putting on there is overriding the me.connect. I'm not quite sure what you mean by "decorate and package" data. Would it in any way be better for the car system to send/receive data through the me.connect system instead of interrogating the OBD2 system directly?

    – Pᴀᴜʟsᴛᴇʀ2
    4 hours ago








1




1





Welcome to Motor Vehicle Maintenance & Repair! Realistically to me, you should be able to do this without conflict. I mean, the OBD2 system runs over a CAN Bus with many different computers vying for time on the Bus. As long as you are requesting information correctly through the bus, I'd think you shouldn't have an issue. I'd suspect your "reader" is trying to take over instead of just reading. I'm no expert, so this is just conjecture ... leaving it as a comment.

– Pᴀᴜʟsᴛᴇʀ2
7 hours ago







Welcome to Motor Vehicle Maintenance & Repair! Realistically to me, you should be able to do this without conflict. I mean, the OBD2 system runs over a CAN Bus with many different computers vying for time on the Bus. As long as you are requesting information correctly through the bus, I'd think you shouldn't have an issue. I'd suspect your "reader" is trying to take over instead of just reading. I'm no expert, so this is just conjecture ... leaving it as a comment.

– Pᴀᴜʟsᴛᴇʀ2
7 hours ago















Thank you @Pᴀᴜʟsᴛᴇʀ2. What do you mean with "...trying to take over..."?

– Luca Rasconi
6 hours ago





Thank you @Pᴀᴜʟsᴛᴇʀ2. What do you mean with "...trying to take over..."?

– Luca Rasconi
6 hours ago













How are the two devices connected? As Mike and JPhi1618 have said, there's usually only one port. If you've added some kind of adaptor to allow two devices to connect to one port, this might not be passing all the manufacturer-specific pins correctly?

– Nick C
5 hours ago





How are the two devices connected? As Mike and JPhi1618 have said, there's usually only one port. If you've added some kind of adaptor to allow two devices to connect to one port, this might not be passing all the manufacturer-specific pins correctly?

– Nick C
5 hours ago













@LucaRasconi - Obviously there's a conflict with what you're putting on your CANBus and what already exists on the system. I'm suggesting whatever your putting on there is overriding the me.connect. I'm not quite sure what you mean by "decorate and package" data. Would it in any way be better for the car system to send/receive data through the me.connect system instead of interrogating the OBD2 system directly?

– Pᴀᴜʟsᴛᴇʀ2
4 hours ago





@LucaRasconi - Obviously there's a conflict with what you're putting on your CANBus and what already exists on the system. I'm suggesting whatever your putting on there is overriding the me.connect. I'm not quite sure what you mean by "decorate and package" data. Would it in any way be better for the car system to send/receive data through the me.connect system instead of interrogating the OBD2 system directly?

– Pᴀᴜʟsᴛᴇʀ2
4 hours ago










1 Answer
1






active

oldest

votes


















3














Because having two devices connected at the same time can possibly change the behavior of the host system in some situations...



The manufacturer may only expect one device to be connected at any one time (whether it be a diagnostic reader, insurance recorder, fleet management recorder etc etc) - and not tested or warranted the performance for 2 or more devices to be connected at the same time... If you step out of the envelope then don't expect normal behavior.






share|improve this answer


























  • How can a manufacterer expect only one device? I mean a diagnostic check can use obd port, insurances may suggest you to use an obd device, fleet management software can rely on data gathered from obd, for the taxi we can have same... there are several use cases where you can plug obd... I don't know

    – Luca Rasconi
    6 hours ago






  • 1





    One device connected at any one time... You can have obd devices for different tasks, that's not an issue.

    – Solar Mike
    6 hours ago






  • 1





    There is only one port, so they assume only one device at a time is able to connect. If there was a port under the dash and another one in the engine bay, they would have to assume both could be used at one time and deal with it.

    – JPhi1618
    6 hours ago






  • 1





    @JPhi1618 and if they provide two ports then they would make sure there was "termination" or suitable to prevent transmission errors...

    – Solar Mike
    6 hours ago











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1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes









3














Because having two devices connected at the same time can possibly change the behavior of the host system in some situations...



The manufacturer may only expect one device to be connected at any one time (whether it be a diagnostic reader, insurance recorder, fleet management recorder etc etc) - and not tested or warranted the performance for 2 or more devices to be connected at the same time... If you step out of the envelope then don't expect normal behavior.






share|improve this answer


























  • How can a manufacterer expect only one device? I mean a diagnostic check can use obd port, insurances may suggest you to use an obd device, fleet management software can rely on data gathered from obd, for the taxi we can have same... there are several use cases where you can plug obd... I don't know

    – Luca Rasconi
    6 hours ago






  • 1





    One device connected at any one time... You can have obd devices for different tasks, that's not an issue.

    – Solar Mike
    6 hours ago






  • 1





    There is only one port, so they assume only one device at a time is able to connect. If there was a port under the dash and another one in the engine bay, they would have to assume both could be used at one time and deal with it.

    – JPhi1618
    6 hours ago






  • 1





    @JPhi1618 and if they provide two ports then they would make sure there was "termination" or suitable to prevent transmission errors...

    – Solar Mike
    6 hours ago
















3














Because having two devices connected at the same time can possibly change the behavior of the host system in some situations...



The manufacturer may only expect one device to be connected at any one time (whether it be a diagnostic reader, insurance recorder, fleet management recorder etc etc) - and not tested or warranted the performance for 2 or more devices to be connected at the same time... If you step out of the envelope then don't expect normal behavior.






share|improve this answer


























  • How can a manufacterer expect only one device? I mean a diagnostic check can use obd port, insurances may suggest you to use an obd device, fleet management software can rely on data gathered from obd, for the taxi we can have same... there are several use cases where you can plug obd... I don't know

    – Luca Rasconi
    6 hours ago






  • 1





    One device connected at any one time... You can have obd devices for different tasks, that's not an issue.

    – Solar Mike
    6 hours ago






  • 1





    There is only one port, so they assume only one device at a time is able to connect. If there was a port under the dash and another one in the engine bay, they would have to assume both could be used at one time and deal with it.

    – JPhi1618
    6 hours ago






  • 1





    @JPhi1618 and if they provide two ports then they would make sure there was "termination" or suitable to prevent transmission errors...

    – Solar Mike
    6 hours ago














3












3








3







Because having two devices connected at the same time can possibly change the behavior of the host system in some situations...



The manufacturer may only expect one device to be connected at any one time (whether it be a diagnostic reader, insurance recorder, fleet management recorder etc etc) - and not tested or warranted the performance for 2 or more devices to be connected at the same time... If you step out of the envelope then don't expect normal behavior.






share|improve this answer















Because having two devices connected at the same time can possibly change the behavior of the host system in some situations...



The manufacturer may only expect one device to be connected at any one time (whether it be a diagnostic reader, insurance recorder, fleet management recorder etc etc) - and not tested or warranted the performance for 2 or more devices to be connected at the same time... If you step out of the envelope then don't expect normal behavior.







share|improve this answer














share|improve this answer



share|improve this answer








edited 6 hours ago

























answered 7 hours ago









Solar MikeSolar Mike

19k21134




19k21134













  • How can a manufacterer expect only one device? I mean a diagnostic check can use obd port, insurances may suggest you to use an obd device, fleet management software can rely on data gathered from obd, for the taxi we can have same... there are several use cases where you can plug obd... I don't know

    – Luca Rasconi
    6 hours ago






  • 1





    One device connected at any one time... You can have obd devices for different tasks, that's not an issue.

    – Solar Mike
    6 hours ago






  • 1





    There is only one port, so they assume only one device at a time is able to connect. If there was a port under the dash and another one in the engine bay, they would have to assume both could be used at one time and deal with it.

    – JPhi1618
    6 hours ago






  • 1





    @JPhi1618 and if they provide two ports then they would make sure there was "termination" or suitable to prevent transmission errors...

    – Solar Mike
    6 hours ago



















  • How can a manufacterer expect only one device? I mean a diagnostic check can use obd port, insurances may suggest you to use an obd device, fleet management software can rely on data gathered from obd, for the taxi we can have same... there are several use cases where you can plug obd... I don't know

    – Luca Rasconi
    6 hours ago






  • 1





    One device connected at any one time... You can have obd devices for different tasks, that's not an issue.

    – Solar Mike
    6 hours ago






  • 1





    There is only one port, so they assume only one device at a time is able to connect. If there was a port under the dash and another one in the engine bay, they would have to assume both could be used at one time and deal with it.

    – JPhi1618
    6 hours ago






  • 1





    @JPhi1618 and if they provide two ports then they would make sure there was "termination" or suitable to prevent transmission errors...

    – Solar Mike
    6 hours ago

















How can a manufacterer expect only one device? I mean a diagnostic check can use obd port, insurances may suggest you to use an obd device, fleet management software can rely on data gathered from obd, for the taxi we can have same... there are several use cases where you can plug obd... I don't know

– Luca Rasconi
6 hours ago





How can a manufacterer expect only one device? I mean a diagnostic check can use obd port, insurances may suggest you to use an obd device, fleet management software can rely on data gathered from obd, for the taxi we can have same... there are several use cases where you can plug obd... I don't know

– Luca Rasconi
6 hours ago




1




1





One device connected at any one time... You can have obd devices for different tasks, that's not an issue.

– Solar Mike
6 hours ago





One device connected at any one time... You can have obd devices for different tasks, that's not an issue.

– Solar Mike
6 hours ago




1




1





There is only one port, so they assume only one device at a time is able to connect. If there was a port under the dash and another one in the engine bay, they would have to assume both could be used at one time and deal with it.

– JPhi1618
6 hours ago





There is only one port, so they assume only one device at a time is able to connect. If there was a port under the dash and another one in the engine bay, they would have to assume both could be used at one time and deal with it.

– JPhi1618
6 hours ago




1




1





@JPhi1618 and if they provide two ports then they would make sure there was "termination" or suitable to prevent transmission errors...

– Solar Mike
6 hours ago





@JPhi1618 and if they provide two ports then they would make sure there was "termination" or suitable to prevent transmission errors...

– Solar Mike
6 hours ago










Luca Rasconi is a new contributor. Be nice, and check out our Code of Conduct.










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