# PS Module

All power supply (PS) modules have the following mandatory standard parameters:

| Parameter      | Meaning                                                                                                                                                                                                                                                                                                                        | Examples                                                       |
| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | -------------------------------------------------------------- |
| Resource       | The connection information needed to connect to this device. Depending on the type of device this can be a COM port, a GPIB address, an IP address or something else. Most drivers are based on VISA, which brings its own syntax to provide a GPIB or IP address. The VISA resource names can usually be looked up in NI Max. | <p>COM1<br>GPIB0::1::INSTR<br>TCPIP::192.168.222.50::INSTR</p> |
| NominalVoltage | The initial voltage which should be set during device initialization.                                                                                                                                                                                                                                                          | 12.0                                                           |
| MinVoltage     | The lower voltage limit in V. This value can be changed through the [LTT GUI](/ltt/documentation/ltt-gui-manual/lttgui/dialogs/f10testparameterconfiguration.md). The GUI will stop all running tests if this limit will be violated.                                                                                          | 0                                                              |
| MaxVoltage     | The upper voltage limit in V. This value can be changed through the [LTT GUI](/ltt/documentation/ltt-gui-manual/lttgui/dialogs/f10testparameterconfiguration.md). The GUI will stop all running tests if this limit will be violated.                                                                                          | 19.0                                                           |
| CurrentLimit   | The max. current the power supply will regulate to in current mode (CC). This value can be changed through the [LTT GUI](/ltt/documentation/ltt-gui-manual/lttgui/dialogs/f10testparameterconfiguration.md). If the actual load is greater than this current the voltage will drop, leading to malfunctions.                   | 100                                                            |

Depending on the specific PS module, there might be additional parameters, which are described [here](/ltt/documentation/ltt-gui-manual/configuration/moduleconfiguration/ps/ps-parameters.md).

Per default a power supply configured here is controlled by the underlying LTT software layer. This means the PS is **automatically initialized and configured to the provided parameters**. Nevertheless, in your [testplan](/ltt/documentation/ltt-gui-manual/teststand.md) you can still change voltage and/or current during runtime, as well as access the latest values read from that PS (see [here](/ltt/documentation/ltt-gui-manual/teststand/hardware-control.md)). But you have **no control** over when the PS is initialized/closed and when the output is turned on/off.

## TestStand-only control

There are situations in which you might need **more control over your power supply** from within TestStand. For such situations you can provide the `tsonly="true"` attribute to the `Module` node.

```xml
<Module name="PS1" tsonly="true">
...
</Module>
```

If you do so, **you are in charge** of initializing, setting and closing the power supply properly. [Read here to learn how to do](/ltt/documentation/ltt-gui-manual/teststand/hardware-control.md).

{% hint style="info" %}
You can access the PS control panel through [GUI](/ltt/documentation/ltt-gui-manual/lttgui/hwcontrol/ps-control-gui.md) and also via [TestStand](/ltt/documentation/ltt-gui-manual/teststand/hardware-control.md). However, the control panel is not available for self-controlled (`tsonly="true"`) power supplies.
{% endhint %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.irs.systems/ltt/documentation/ltt-gui-manual/configuration/moduleconfiguration/ps.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.