HMP4040 User Interface

[Baltazar]

I am thinking about acquiring a R&S HMP4040 power supply. Can anyone with user experience answer this:

1. How can you independently turn a given channel's output on & off? The manual states:

The Output key turns on the outputs of all activated channels and supplies the connected loads.

This is not clear to me - which are the "activated channels"? "Activated" doesn't mean "output on", right? Can you e.g. turn Ch1 output on, then turn Ch2 output on as well, and then turn Ch1 output off while keeping Ch2 output on? What would be the keypress sequence for that? And how to turn e.g. Ch1+Ch2+Ch3 outputs on & off at the same time? I want to check if the UI is intuitive enough.

2. Can you at any moment clearly see which channels' outputs are on are which are off? I would think the "Ch1"..."Ch4" key illumination indicates this but again according to the manual:

Selecting the channels
►    Press the channel key, e.g. Ch1.
An active channel key is illuminated in green.


So the light goes on when the channel is activated, not when the output goes on.

[rf-messkopf]

I have a HMP4040. Normally I handle instruments rather intuitively without much thinking, so I'll see if I can answer this from memory. 

This is not clear to me - which are the "activated channels"? "Activated" doesn't mean "output on", right? Can you e.g. turn Ch1 output on, then turn Ch2 output on as well, and then turn Ch1 output off while keeping Ch2 output on? What would be the keypress sequence for that? And how to turn e.g. Ch1+Ch2+Ch3 outputs on & off at the same time? I want to check if the UI is intuitive enough.

Suppose the output on button is selected off (i.e., dark). Then you can toggle the individual channel buttons ("activate" them) by pushing them. They turn blue when activated. When you hit output on, the activated channels are switched on. The channel buttons then turn green when in CV mode or red when in CC mode.

2. Can you at any moment clearly see which channels' outputs are on are which are off? I would think the "Ch1"..."Ch4" key illumination indicates this but again according to the manual:

Yes. A channel that is off (not outputting) or not activated (when output on is not selected) is dark.

So the light goes on when the channel is activated, not when the output goes on.

The light is on when it is activated or the output is on. Only the color is different. As I said, blue: activated, green/red: on and outputting.

The buttons also have a third mode: they select to which channel the keypad and rotary encoder refers. If you hit the voltage or current button, the a channel button starts blinking, and a button push can select another channel. There is a timeout for this mode, and I think it can also be set to infinite timeout.

I rather like the user interface, especially the numeric keypad which is really handy for entering parameters. It needs some time to get used to though, and an inexperienced user can easily turn the wrong channel on or alter its parameters.

[Baltazar]

Suppose the output on button is selected off (i.e., dark). Then you can toggle the individual channel buttons ("activate" them) by pushing them. They turn blue when activated. When you hit output on, the activated channels are switched on. The channel buttons then turn green when in CV mode or red when in CC mode.

Let me check my understanding. Let's say Ch1 & Ch2 outputs are ON in CV mode, thus buttons Ch1 & Ch2 are green. I want to turn Ch2 output off:
- I press the "Ch2" button to "activate" channel nr. 2 and the "Ch2" button goes blue.
- I press the "Output" button. Output 2 is turned off and button "Ch2" goes dark. "Ch1" button remains green.
Is that right?

What about the "Output" button illumination - what does it tell when this one is white?

[rf-messkopf]

Opps, I just tried it. An "activated" channel button is not blue, but green. Sorry. Let me try to summarize the behavior in a systematic way.

Suppose the "Output" button is selected off (not illuminated):
- When a channel button is pressed, it is "activated" and lights green, but the channel is not turned on. Another button press deactivates the channel.

When the "Output" button is pressed when it is off:
- The "Output" button lights up white.
- All "activated" channels (with buttons illuminated green) are turned on; when in CV mode, they remain green, when in CC mode, they light up red.

When the "Output" button is on:
- A press on an button of a channel that is on (illuminated green or red) turns that channel off, and the button becomes dark.
- A press on a button of a channel that is off (dark) turns that channel on, the button becomes green (CV) or red (CV).
- A press on the "Output" button turns all channels of. The "Output" button turns dark, and the channel buttons that were on become green ("activated"), the others that were off remain dark.

When the "voltage" or "current" button is pressed:
- When the "Output" is off (button dark), one channel button lights up blue, and its voltage or current can be varied with the keypad or rotary encoder. A press on another channel button will light that button blue and the parameters can be varied alike. This works no matter if the channel was "activated" before. I.e., you can change the parameters of a inactivated channel.
- When the "Output" is on (button white), the behavior is the same, except that a channel button whose output is on flashes between blue and green/red. So the voltage and current of a channel can be varied while it is on, and you can see to which channel the keypad or encoder refer, and you can see it the supply is in CV or CC mode. You can also vary the parameters of a channel that is off while other channels are on and outputting.
- When you change parameters of a channel, a cursor is also displayed in the dot matrix LCD, and you see there to which channel the keypad and rotary encoder refer. Also, the cursor keys around the rotary encoder light up.
- With a press of the "Track" button after the "Voltage" or "Current" button, you can select several channel buttons to blue. The "Track" button then lights white, and subsequent keypad and rotary encoder entries refers all of these channels selected to blue. This behavior remains until "Track" is selected off by another press.

Sounds complicated, but actually I find it quite intuitive.

Let me check my understanding. Let's say Ch1 & Ch2 outputs are ON in CV mode, thus buttons Ch1 & Ch2 are green. I want to turn Ch2 output off:
- I press the "Ch2" button to "activate" channel nr. 2 and the "Ch2" button goes blue.
- I press the "Output" button. Output 2 is turned off and button "Ch2" goes dark. "Ch1" button remains green.
Is that right?

Not quite. Suppose the "Output" button is on and channel 1 and channel 2 are on in CV mode (green). When you press "Ch2", then this output is turned off and the button goes dark. A subsequent press on the "Output" button turns off all channels (only the remaining channel 1 in this example) and the "Ch1" button remains green, and the "Output" button goes dark. Another press on "Output" turns channel 1 on, "Ch1" lights green or red, and "Output" lights white.

What about the "Output" button illumination - what does it tell when this one is white?

"Output" button dark: All channels off, "Output" button white: the channels with red/green buttons are on and running in CV/CC mode according to color.

Edit: To make a long story short: When "Output" is off, the channel buttons select which channels you want to turn on when pressing "Output", and when "Output" is on, the channel buttons actually turn individual channels on or off. As I said, all very intuitive.

[pdenisowski]

Maybe this might help

https://youtube.com/watch?v=bVv4brlyCz8

I don’t have one in my office right now, but the other replies sound correct to me (and I cover some of these in the video as well).

[Baltazar]

Thanks for the detailed description and for the link, it is clear now.