Author Topic: IPS-405 Programable Power Supply, RS232 Interface  (Read 286 times)

0 Members and 1 Guest are viewing this topic.

Offline dmg0345

  • Contributor
  • Posts: 5
  • Country: es
IPS-405 Programable Power Supply, RS232 Interface
« on: June 16, 2021, 04:15:53 pm »
Hi everyone,

The IPS-405 and related are quite popular power supplies and I was hoping someone could help me find a cable to properly connect to this power supply through the RS232 interface from a USB port in my computer.

I have an ISOTECH IPS-405 Power Supply like this one: https://www.enrgtech.co.uk/buy/product/ET13984959/IPS-405.

I am familiar with serial ports, UARTs, COM ports and the like however I am struggling to find a RS232 to USB for this PSU, from the manual:



And this is the connector on the back of the PSU:



I find it quite atypical and non standard, this is neither a straight through cable nor a null modem cable, and I am confused as to why I need 12V on that pin, and not anything between 5V and 15V as defined in the RS232 spec for a high level, I have read that some old devices only worked with 12V and rejected any other voltage, I suspect the RXD and TXD pins might work with this voltage too.

Has anyone with a similar PSU recommend any RS232 to USB cable for this board? It does look like I need a custom one, but I hardly believe that this was the expected use case by the manufacturers of this PSU, I am probably missing something.

Thank you for your time.
 

Online bingo600

  • Super Contributor
  • ***
  • Posts: 1623
  • Country: dk
Re: IPS-405 Programable Power Supply, RS232 Interface
« Reply #1 on: June 16, 2021, 06:13:11 pm »
Guess about the 12v.

It powers an opto isolation thingy in the PSU , so your computer & psu are isolated from each other.

/Bingo
 
The following users thanked this post: dmg0345

Offline dmg0345

  • Contributor
  • Posts: 5
  • Country: es
Re: IPS-405 Programable Power Supply, RS232 Interface
« Reply #2 on: June 16, 2021, 07:23:00 pm »
Guess about the 12v.

It powers an opto isolation thingy in the PSU , so your computer & psu are isolated from each other.

/Bingo

You are probably right, I came across what seems to be the schematics of this PSU (or a very similar model) and noticed the following:



I thought the 12V signal was DCD, but looking at the schematics it does not look like that, it does something with the optocouples there.

So I guess this provides some clarity, but I still wonder what kind of wire where the original manufacturers expected people to use because I can't find any and I would rather avoid doing something custom.

EDIT: Forum seems to be resizing the image, the image can be seen here: https://ibb.co/NxJ1xpt
« Last Edit: June 16, 2021, 07:29:37 pm by dmg0345 »
 

Offline dmg0345

  • Contributor
  • Posts: 5
  • Country: es
Re: IPS-405 Programable Power Supply, RS232 Interface
« Reply #3 on: June 16, 2021, 08:16:58 pm »
I also looked at the datasheet of the Winbond UC with the TXD/RXD signals, and noticed that the ranges of Input/Output for the TXD and RXD signals are in the range of 0V to 5V it seems: https://ibb.co/n3Ybpfq.

So it looks like a 12V input, a normal UART and a RS232 connector.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf