Qbus Protocol

[mathewprince]

Does anyone know what is QBus, its just a single line kind of serial bus...any one know the protocol?

 

[Pommie]

Here you go. Clicky.

Mike.

 

[mathewprince]

Mike,

there is no info about the protocol and the signal.. I have gone through each search results..

 

[Pommie]

The second link has a good description. It appears to be a very old system used on 1980s machines.

Mike.

 

[mathewprince]

That is an old computer bus.. but this I am talking is only one wire and I think its a serial communication bus.. I have one device and one of its wire marked as Qbus and I can connect the device to a PC via RS232 through a converter provided by the same company.only Qbus wire and GND is connected to that box. but I can access all the info from that device . also i can program a controller in that device through this Qbus line.

 

[Pommie]

A link to the device would be useful. The only 1 wire bus I'm aware of is the Dallas One Wire (OW) bus. Does the device have a 64 bit ID?

Mike.

 

[mathewprince]

its an OIL & GAS Directional sensor I don't have any details from the supplier side.. tats why I am trying to get the info about it.. when I trace the connector ..I got only this info..its communicating using this line.. I only have the connector details that says QBus..GND, Battery etc..

 

[JimB]

QBus was a mini-computer data and address bus from the days before microprocessors.
Look here:
Q-Bus - Wikipedia, the free encyclopedia

It does not make sense to me that this would be extended to an external sensor, how many pins are there in this "QBus" connector?

I would expect a controller card which connects to the QBus which then has some isolated interface to the remote device.

Can you give some more details of this "oil and gas directional sensor" ?

JimB

 

[mathewprince]

I read that in wiki..but this is only one wire and gnd.. its a serial bus..

 

[Pommie]

I only have the connector details that says QBus..GND, Battery etc..

This suggests that there are more than two connections. What are they?

Mike.

 

[mathewprince]

for the Qbus, there is only one line all other lines I know what it is..and for the communication with PC only this line and GND are used.. no other lines are connected..

 

[Diver300]

https://www.electro-tech-online.com/threads/ebus.34430/
I asked about something similar a couple of years ago and no-one answered.

I think that there are a lot of proprietary serial busses that no-one has ever published the specifications for. If the original company decided that they would only be making the nodes themselves, or would be charging for use of their design, they keep it secret. I know that my car has a couple of multiplexed busses that aren't CANBUS and are a way of saving wiring, without any thought to expansion.

 

[Mike - K8LH]

Sounds similar to the open-drain or open-collector type Icom C-IV buss, a 1 wire serial bus used in many Icom radios. See Ekki's (DF4OR's) Icom CI-V pages.

When I communicate over a 1-wire serial CI-V interface from the PC side I throw away one RX char for every TX char I send because the interface acts like a loopback connector. On the PIC side I have used a single pin (bit-banged Tx & Rx) or standard two pin hardware USART module with a diode on the Tx pin (due to open-drain bus).

Good luck on your project.

Cheerful regards, Mike

 

[mathewprince]

Thanks mate.. I am going to put scope on that pin while communicating and check wats going on..