J1939

[mckruger]

Hi

 

Has anyone done a project using Canbus J1939 ?

[sensorsolutions]

Yes, mainly for monitoring engine and gearbox ECUs using V130 and V570.

[mckruger]

Yes, mainly for monitoring engine and gearbox ECUs using V130 and V570.

i need to monitor the following on 1 of our trucks

 

a.       Oil pressure (0-5bar)

b.       Low oil pressure alarm

c.       Coolant temperature (0-150°C)

d.       High coolant temperature alarm.

e.       Low air pressure warning. (auxiliary air)

f.        Remote engine stop.

g.       Remote engine start.

h.       Gearbox oil temperature

i.        Gearbox high oil temperature alarm.

 

Could you possible explain or share a demo on how this is done.

I know canbus you have a hex address for example 2C1 that read 8 bytes ( 00000000) whereas if that was for the vehicles lights each byte would do a specific task.

 

I add the configuration of the J1939 from the COM selection in Visilogic but i do not understand what the Transmit PGN and Receive PGN part.

[sensorsolutions]

Hi Mckruger,

You need to get a copy of the SAE J1939-71 standard to ascertain which PGN contains the parameter that you require.

For example Oil Pressure is byte 4 of PGN 65263, it is transmitted at 500ms intervals and has a default priority of 6.

The units are kPa with a resolution of 4 units/bit.

If you have the manuals for the truck you are working on the information should be in them.

Once you have entered the information in the configuration the rest is taken care of by Visilogic.

I hope this is of some use to you.

[mckruger]

Hi Mckruger,

You need to get a copy of the SAE J1939-71 standard to ascertain which PGN contains the parameter that you require.

For example Oil Pressure is byte 4 of PGN 65263, it is transmitted at 500ms intervals and has a default priority of 6.

The units are kPa with a resolution of 4 units/bit.

If you have the manuals for the truck you are working on the information should be in them.

Once you have entered the information in the configuration the rest is taken care of by Visilogic.

I hope this is of some use to you.

Thanks for your response

 

I have the information on hand that i need to read from the manufacturer ( as follows )

But i do not know where to place it on the configuration

 

sorry if i come off stupid but im trying to figure this out by myself without previous knowledge of J1939

[Simon]

I don't think anyone would think you stupid, it's a steep learning curve trying to figure this out from the beginning.  What you have posted looks OK, from a quick glance.

 

Once you have it working the PLC will collect the PGN data from the field, capture the 8 data bytes of the PGN and save them to the memory operands you have nomiated (which is not in the screenshot you posted, you need to scroll down).  Make sure you allow 8 bytes of space (4x MI or 2x ML or DW) otherwise your data will be messed up.  For example if you nomiate MI10 as the pointer target, also leave MI11-13 unused.  I suggest giving them labels so the system sees them as occupied.

 

After that it is up to you to read out the bits and bytes from that 8-byte data block, based on the SPNs that are defined for that PGN.

 

I would put a counter on your receive bit (MB0) and reset it every time it goes high, so you can see if your are receiving data.

If you have a colour PLC it has a built-in CAN bus monitor, that lets you see the raw CAN data from the Info mode.

 

(I have had only a quick try with J1939, so am happy to be corrected on any point )