RS232 connection with NI 9870 / terminates cRIO connection

[ChristophBielefeld]

Hey,

We are working on a project including a power supply (with an RS232 interface card), a cRIO 9024 and the RS232 Serial Module 9870.

It is possible to read values from the power supply via those components but writing new values to the power supply is terminating the connection to the cRIO. (without any error message, just a lost connection)

The used drivers are working properly (reading and writing) if we connect the power source directly to the RS232 port of a Computer running Windows.

Are there any diffrences between the 9870 RS232 Port on the C Series Modules and the PC Port which we should know of?

Or are there any Software based diffrences which could cause this error?

Best regards,

Chris

[Wayne.C]

Did you connect an isolated DC supply to the 9870?

[ChristophBielefeld]

I connected it to the same 24V supply which serves as the power supply for the cRIO.

It's this one: http://www.block.eu/en_US/products/power_supplies/product/2359334/

Do you think thats a sufficient method?

Best regards and thanks so much for your help

Chris

[crossrulz]

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@ChristophBielefeld wrote:

I connected it to the same 24V supply which serves as the power supply for the cRIO.

It's this one: http://www.block.eu/en_US/products/power_supplies/product/2359334/

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Which one?  There's 13 options there.  I'd have to look at the specs for the cRIO and the module, but you could be hitting the current limit of your power supply.

[ChristophBielefeld]

oh I'm sorry for the inconvenience.

it's this one PVSE 230/24-5

thanks so much 🙂

strange thing is that the reading of values at the (controlled) target power supply the (EA-PS 8080 120 U) works just fine. Just the writing of setpoint doesn't.

[Wayne.C]

Suggest you double check your connections between 9870 and power supply.  Handshake lines?

[ChristophBielefeld]

Ok I'll Check the connections first of all. I did google the handshake lines configuration but didn't get any closer to understanding. Support of the EA PS8080 power supply said that their rs232 interface card doesn't use handshaking. How do I configure it for the cRIO or the ni9879?

Best regards
Chris

[ChristophBielefeld]

Hey
So we checked handshake lines and power connection. Everything is connected and set up the way it should be. The controller is still jumping into safe mode after trying to write any value to the register of the ea power supply. Also tried to reset the cRIO software. Still can't figure out the difference between PC rs port and the ni 9870 access to the ea power supply. Would be so grateful for any suggestions. 🙂

[Wayne.C]

Chris,

Only thing I can think of is a small experiement using a separate DC supply to power the 9870 module.  Wondering if any of the symptoms will change.

[ChristophBielefeld]

Hey,

we tried the different DC supply but it didn't make any difference. Still the same problem.

cRIO error protocol shows:

<DEBUG_OUTPUT>
10/07/14 12:50:38.590 PM
DAbort 0xDAAD3994: ConvertNum called with Empty Data
source/NumericSupport.cpp(88) : DAbort 0xDAAD3994: ConvertNum called with Empty Data

does this have anything to do with our problem?

Thanks for your support 🙂