Fp- Explorer read zero values instead of correct values

[Rainer E.]

Hi folks,
I'm having troubles reading out the measured analog values from the
input ports of several FP-AI-110.

I used the FP- Explorer V2.x first and updated to V3.02 later without
any success.
I have two FP- banks, each connected with a FP-1001 to a RS/EIA-422
network.
One bank has three FP-AI-110, the other also three FP-AI-110 plus two
FP-SG-140.

All modules are recognized correctly by the FP- Explorer and I
configurated the channels to desired ranges. After configuring, I saved
the iak- file. Monitoring the module channels works fine (I thought at
first), at least values showed (mostly 0,000001 +/- 1 digit). No
timeout, overrange or any other error was displayed.
The FP-SG-140 (Strain gauge) modules showed overange with values about
-3,xxx, which was correct, because there were no strain gauges connected
to their inputs.

Strangely behaving began, as I put analog voltages to the
input-connector of the FP-AI-110. Values where monitored contiously by
the FP-Explorer, but the voltage values always stayed at 0.000001, no
matter which voltage input range was configured, or which voltage was
applied at the input connector. Replacing the mounted modules by new-
out-of-the-box ones didn't help.

Then I went into the channel configuration of the FP- Explorer again,
just to show the config. of one channel of a module and clicked on
. After that, this channel and all others of the selected module
where monitored correctly. I did the same for all other FP-AI-110
modules and the behaved the same.
Rebooting the computer, or just calling a labview application (with
fp-open-tag-read and -close) to monitor the channels, started the
erroneous behaving again.

So what is happening? Why do the these modules behave like this? What is
the solution?
Might there be a chance for a workaround, by saving the module
configuration as startup values into the module- eeprom? And how does
this storing work. Somebody told me, it should be possible, using the
FP-Exlorer 3.01 or above. But I didn't find out how to do so, whether
with the V2.x, nore with the V3.02.

Btw,
- I'm using LabVIEW 6.02 for programming
- and a ENET-485/4 to connect to the RS/EIA-422 Bus

Is there anybody out there with any helping ideas?
I'm running out of time (and coffee) and my boss is allready...

Further explanations:
RS/EIA-422 means 4-wire, fullduplex, one master. (Which FP- modules are
using)
RS/EIA-485 means 2-wire, halfduplex, multimaster possible.
The way Ni, and others talk and write about RS-485 is often wrong! One
place where NI shows the RS-XXX correctly is in the helpfile for the
ENET-485, where the pinout of the 9-pin Sub-D- RS-485/422/232 connector
is showed.

Waiting for suggestions,

Rainer

[Aaron_G]

Rainer,

It sounds like the configuration is not being maintained on one side of the system. In order for the PC to maintain the configuration, you need to make sure that you save the IAK file and use the same one (or one with the same configuration settings) each time. This is important because the FieldPoint serial modules send all analog data as raw 16 bit data and the scaling is done on the host side.

On the FieldPoint side of things, you need to make sure that the FP-1001 is configured so that it retains the channel range and attributes that you have configured. FieldPoint network modules support two power-on configurations; factory default and user defined. Factory default on the FP-AI-110 is for the channels to be configured in the 0-21 mA range (if I
recall correctly). This would easily explain why you are seeing zero (since you have the voltage and not the current channels wired). To configure the FP-1001 to use the User Defined configuration, right click on the FP-1001 @X in FieldPoint Explorer and choose Edit This Device. There is a checkbox that says "Factory Configuration", un-check it. Press OK and everything is set. You should not need to re-configure your modules as FieldPoint always maintains both settings. You may want to double check everything in case one of the settings is no longer what you want from your troubleshooting.

Regards,
Aaron

[Rainer E.]

Hi Aaron,
thanks for the answer. I'll try out your suggestion about the userdefined
config., when I'm at work tomorrow again. I hope you're right.
About the IAK file: I only have one, so there is no confusing.

Rainer

[Rainer Ehrt]

Hi Aaron,
as I replied yesterday, I looked at the FP- Explorer config. and you where
right!
"Factory Configuration" was checked. After unchecking, everything worked
well with the Fp- Explorer and with my LabVIEW application as well.

But there is still one thing for NI to correct. If "Factory Configuration"
is checked, the modules seems to be reset to the factory config., but the
FP Explorer shows the user- range configuration. This means, the module is
resettet to 0-20 mA, but the range showing of the FP-Explorer says +/- 5V.
So the module measures a >>current of 0.000001 V>> ;)))

Thanks and bye,
Rainer

[Aaron_G]

Rainer,

FieldPoint Explorer is designed to allow offline configuration of modules which means the module and the IAK may deliberately be out of sync. Whenever you choose Channel Configuration on an I/O module is when the syncrhonization check if performed. You may have noticed that occasionally you get a message stating that the module and FieldPoint Explorer have different settings where it asks you to choose File, Module or Cancel. This is the result of the synchronization check. This is the designed and desired behavior. If you want to synchronize an entire bank at once, you can choose Find Devices from the Comm Resource and it will update the IAK with the current settings that are in each module (although this approach doesn't give you no
tice that some settings are out of synch).

Regards,
Aaron

[Rainer Ehrt]

Hi Aaron,


> You may have noticed that
> occasionally you get a message stating that the module and FieldPoint
> Explorer have different settings where it asks you to choose File,
> Module or Cancel.

Yes, as I still had the "factory default" checked, this message appeared,
asking which config to choose, module, or file.
So I chose file and the Explorer displayed the input ranges I configured
previously. For me it looked like the FP-explorer reading the IAK file,
displaying the values he found there and configuring the modules like it
was stored in the IAK file.
But in fact the FP Explorer didn't. He forgot to configure the modules
with the data he DID read from the file. I can't see any reason for the
explorer displaying things but n
ot doing them.
Well, because of your hint I have the solution which works for me. But
things are confusing for novices.

Rainer Ehrt