Hello All,
I have got a application that the customer converts j1939 signals on 3B6 controller to RS485 signals , and then drives some PVA gauges such as tachometer, oil pressure ,water temperature and so on. They don’t like to use PV101 or PV750 but use a J1939 to RS485 translation module. Now it seems to translate successfully ,because they can see some data on RS485 monitoring software, but the PVA gauges do not have any response. If you have any good advice ,please help me .
Thanks ,
Best Regards;
Peter Fu
FWMURPHY Hangzhou

Is the Serial Port Protocol set to "PVA Gauge" in the Environment Setup section?

bseidl

bseidl wrote:Is the Serial Port Protocol set to "PVA Gauge" in the Environment Setup section?

bseidl

Hi Bseidl,
I will check if they set the serial port protcocol to "PVA gauges". But the customer and I both can't understand the Modbus Holding Registers in the attachement. For example , the register of engine speed is 40004, what is it mean, and how to set the RS485 data with 40004? What is the value for data not available with FFFh,-1d?
There is nobody knowing the RS485 application ,so it very trouble me .If you know how to resolve this problem,please teach me.
Thanks and Best Regards;
Peter Fu
FWMURPHY Hangzhou

Hi Bseidl,
I will check if they set the serial port protocol to "PVA Gauges". But the customer and I both can't understand the Modbus Holding Registers in the attachement. For example, the register of engine speed is 40004, what is it mean, and how to set the RS485 data with 40004? What the "value for data not available with FFFh,1d" mean?
There is no one to know RS485, so it very trouble me . If you understand RS485 well, please teach me . How to translate from j1939 into RS485 in the PV101? If you have any good advice ,please let me know .
Thanks very much.
Peter Fu
FWMURPHY Hangzhou

Peter,

In general on this I would recommend contacting Technical Support.

Concerning the pv101:

1. The modbus map you attached is for the pv101 only, it is not supported by the pv750.

2. The modbus registers for the pv101 are read only, you can not set values into the pv101 using the modbus registers.

3. The 0xFFFFh, -1d means when the value is invalid or is no longer being sent the 16 bit register is set to FFFF hex which is -1 decimal. So for example, if engine speed is not being received, 40004 is equal to FFFF in hex.

4. With the pv101 you read in J1939 parameters and drive PVA gauges. This conversion happens automatically if the rs485 port is configured for PVA gauges. The port is configured for this by default.

5. You can not set engine speed with register 40004, you can read engine speed with register 40004. The modbus registers are read only.

6. On the pv101 you can not use the rs485 port as something that drives PVA gauges and a modbus port at the same time, it has to be configured for one way or the other.

7. The PV101 automatically translates J1939 to modbus which is sent over the serial rs485 line. So if you are receiving engine speed through j1939 it will output engine speed on modbus at register 40004. The pv101 acts as a modbus slave, so to get this information you poll the pv101 with a modbus master.

The pv750 is similar except it does not have a fixed built in modbus map. You have the capability to configure it the way you want. It also automatically translates j1939 parameters into data to drive the PVA gauges. All you need to do is hook up the PVA gauges correctly and make sure the port is setup for PVA gauges.

I hope this helps. Again, you really should contact Technical Support for more information on this subject. You questions are very typical of the issues they deal with on a daily basis.