Sending command strings to a Sorensen (Ametek / Xantrex) power supply model XDL 35-5TP

[dacad]

Hi all,

I am using the above mentioned power suply to control test units during end of line tests.  I can do all the normal funtions through the manufacturers supplied library of vi's.  The problem is, I need to make sure the voltage being seen by the unit under test is correct and therefor am using the remote sense function on the power supply.  Essentially this runs a pair of sense leads to the point of measurement and allows the power supply to compensate for any voltage drop that is seen in the circuit.

As I am on the downstream side of a solid state relay with the sense leads, I need to cycle the remote sense function so that it is not trying to compensate when the SSR is off (sense would read zero volts and try to run the voltage up to compensate for what it sees as a loss)

The attached diagram shows how I am trying to send the command using the supplied Write Data vi but the power supply never responds to the command.  I have tried different commands with no success and am hoping there is someone that has run across this to give me a hint as to what I am doing wrong.

Any assistance is much appeciated

Doug

[smercurio_fc]

Please do not attach VIs as PDFs. PDFs cannot be debugged, if necessary. Attach the actual VIs or snippets (see the LabVIEW manual on snippets).

I don't have the programming manual, but it would seem to me that your command string is probably lacking some spaces between parameters.

[dacad]

Code is attached including the TQLP library.  The manual states that white space (spaces) are ignored so it does not matter if they are present or not.  I will include that section of the manual as well and near the end of that it shows the syntax for the SENSE command that I am trying to use.

[smercurio_fc]

I don't see anything that jumps out at me as being the obvious error. Does the manual say anything else regarding the operation of the remote sense lines. Like not being able to change it under certain conditions, for example? Have you tried just changing it before doing anything else to the power supply (i.e., right after it's been turned on)?

[dacad]

I am trying to work with support from Sorensen as well and the initial response indicated to check the Mode to make sure the two main outputs were not linked.  (This is a 2 main with 1 aux output supply)  I have confirmed that the Mode is not linked so am waiting to hear back from them for further input.  Other than that, there is nothing else that the manual indicates should cause a problem.

I can change the sense from local to remote on the front panel when the supply is not being controlled remotely but the front panel options are not available for any functions once the remote operation is initiated.

I have tried all sorts of variations with the syntax but I really don't think that is the issue.  I think it is something deeper but was hoping someone here had run into something similar.

Thanks for any continued assistance and I will report back if I get a solution from Sorensen directly.

Doug

[jtraw]

The sense capability is a fucntion of the powers supply itself In order to connect the sense lines to the power supply you had to remove a physical jumper from the terminal block. This means that the power suply will physically regulate itself based on the feed back of the sense lines. When the jumper is in, it takes the input ot regulation right at the jumper. In your case you have connected sense lines to the end of your cable to sense the voltage at then end of the cable. This voltage goes back to the power supply. so if you need 48 VDC at the end of the cable but you drop 8 VDC the power suppy will actually output 56VDC in order to compensate for the loss. the output reading will say its 48 volt dc but if you measure with a multimeter at the back of the supply it will in fact be higher. however, if you connecect the meter to the end of the cable it will show 48vdc. This is of course all load dependent ads current loss in caqbles is a fucnction of the current draw.

[dacad]

There is no jumper on this power supply to engage or disengage remote sense.  It is controlled by the front panel buttons or by software commands.

The orignal question concerned the syntax for controlling the remote sense via software.   I have since resolved this issue.  The power supply is very particular on the format that it receives [serial] commands. When creating a text string in LV, you cn choose to use the built in CR and/or LF text blocks but I found that typing a physical CR into a fixed string ended up working.   That and the correct use of the space bar in the command string allows me to control the R/S programatically.

Welcome to the forum though.