Homebrewed software to communicate with measuring device via Modbus TCP

Dear gentlemen, dear jschulze,

Prior to get ordered and purchased relay output module,
as my computer lacks any rs232 or rs485 port, in order to convert usb to rs485 I posess this converter. Just please have a look at the picture below:
and the rear side with toggles to switch operating mode:

How do you think, is it sufficient to deal with this converter, or do I need to seek and buy another one?
N. Qv.
The converter seems like it should work, but you should test it with known working RS-485 device.

For RS-485, be sure to set the DIP switches properly for RS-485 and connect your wires to the B-, A+, and GND terminals (I believe the TXD and RXD terminals are for RS-232 mode only).

According to the text on the converter, it appears you want DIP switches 3, 4, 8, 7 ON and 1, 2, 5, 6 OFF for USB to RS-485.
Dear jschulze,

As you kindly suggested to compare Adam 4068/4069 to WP 8025 RO I read the set of commands relevant to each one.
I found Adam 4068/4069 supports wider set of commands compared to WP8025RO.
Though among commands for the first as it mentioned on page 83, table 4.17 the "Syncronize samples" and "Read Syncronized Date" are disabled. I have been reflexing what could be the use of those functions?
Also I read that the 4069 module features two additional commands: "Read low pow state" and "Set low pow state". This, as I get could be essential when remotely controlling some distant site to see that power on module is low etc.
The most essential command among others could be "Write safety value" and "Read safety value", if I got it right this implies, that features the latch to prevents module contact(RO) from undesired or accidental trip when module is powered on-off or experiencing communication problems? Did I get it right?
But stil, is the set of commands of Adam 4068/4069 in some means applicable and relevant to WP8025RO? For example, if someone inputs $AAM "Read Module Name" would wellpro module return module name?
The most pleasant surprising thing for me that WP8025RO provides feedback that tells user whether command is accomplished or not, and therefore, as I get, there is no need to buy additional digital input module to check the state of contact(closed/open).

Having reflexed on this for a while, I decided to purchase WP8025RO that would be sufficient introduction.

N. Qv.
Unfortunately, I am by no means an expert with these I/O modules. If you have specific questions regarding their operation, I recommend you contact the vendors directly.

But stil, is the set of commands of Adam 4068/4069 in some means applicable and relevant to WP8025RO? For example, if someone inputs $AAM "Read Module Name" would wellpro module return module name?
The Advantech commands are not compatible with any other vendors' product. The ADAM 4068 module supports two protocols, a proprietary ADAM ASCII protocol and Modbus RTU. The WP8025 supports only Modbus RTU.

The most pleasant surprising thing for me that WP8025RO provides feedback that tells user whether command is accomplished or not, and therefore, as I get, there is no need to buy additional digital input module to check the state of contact(closed/open).
I think you're simply referring to the fact that you can read the Modbus Coil in addition to writing it. This is typically true of almost all Modbus devices, including the ADAM modules (when using the Modbus RTU protocol). However, note that this only provides feedback of the logical state of the contact, which under most conditions will correspond to the physical state of the contact. But if there is damage, malfunction, etc. the module's physical state of the contact may differ from the logical state.
Dear jschulze,
As I intended I have ordered on AE store the WP 8025 RO module.
They commenced with my order on Thuersday and it possibly arrives within November the 1st time span.
Today I have finished with reading the ADAM 4000 series manual which you kindly passed me.
My perception is that it is usefull to read it even though I have chosen Wellpro.
On the mapping table of Modbus protocol for ADAM 4068 module, page 268 it is not clear for me:
1. What is the mapping table of Modbus protocol indended for? And how it could be useful for user?
2. What is ADDR 4X and ADDR X columns stand for, and what is 4X and X factor intended for?
3. What is MEMO column contence for?
4. How to handle this "Mapping table for Modbus Protocol"? What sort of work could be done with its use?
Please have a look at them below:
5. What are these rectangles with arrows above, what do they denote or designate?

N. Qv.
Well, first off, no it is not useful to read another product's Modbus manual if you will be using a different product. You need only be concerned with the manual of the product you're actually using.

But since some of your questions are applicable to other Modbus devices, I'll try to give an answer.

1. What is the mapping table of Modbus protocol indended for? And how it could be useful for user?
A Modbus mapping table, a.k.a register list, details what Modbus registers (Holding Registers/Input Registers) or discretes (Coils/Discrete Inputs) are accessible via Modbus. This is the only way a user knows what data can be accessed on a device, and how the data is accessed.

2. What is ADDR 4X and ADDR X columns stand for, and what is 4X and X factor intended for?
This is standard Modbus reference notation. As follows:
0X - Coils
1X - Discrete Inputs
3X - Input Registers
4X - Holding Registers

Take a look at this thread for an in-depth description of Modbus register numbering.

3. What is MEMO column contence for?
Many times there is a MEMO, NOTES, or DESCRIPTION column in Modbus register tables that give additional detail on the possible values or behavior of the data. If the data is fixed, the fixed value will be shown here. If there are specific meanings to different values, they will be listed here. If there is any scaling done on the value, it will be detailed here.
Dear jschulze,
Today I got received the small parcel with my wp8025ro module included!
I am so pleased to posess it now, after so many days expected for!

Since a while, I have been reflexing on aproach to develop some homebrewed software to make its relay contacts closed and opened upon commands manually issued from PC.
Can you briefly take me to understanding of objective chosen, to have my further activities directed properly?

Your faithfully,
N. Qv.
I recommend first following the instructions in the WP8025ADAM manual for using Wellpro's PC debugging tool to confirm operation between your PC, USB to RS-485 converter, and the WP8025ADAM module.

Next I recommend trying a third-party Modbus tool, such as Modbus Poll, to read and write the 8 Coils (0X type), 1 - 8 (1-based addressing) that correspond to the 8 relays.

Then move on to creating your own software.
Dear jschulze,
I beg your pardon for being absent for a while.
We are installing some RTU alike device on two 35/10 kV substattions to obtain 8-10 binary signals from each site and transmit them with IEC 60870-5-104.
Some time afterwards I return up to objective we have been pondering about.
I don't fully understand what your goal is here, but assuming you're looking for a Modbus RTU to IEC 60870-5-104 gateway, you may want to look at the following.


Also, to make it easier for others (who may have more knowledge on new topics) to assist you and for the sake of members searching the forum in the future with similar questions, please create a new thread next time.
Dear jschulze,
Today I resumed my efforts of interaction with WP8025RO ADAM.
I assembled some circuitry onto my desk.
Please have a look at pics below.
After fulfilling circuitry, I took a manual, it was mentioned that user is supposed to download some software to interact with this module. So I texted query into google bar: 'wp8025ro adam software' it outcomes numerous, one of them was 'github' site, but my computer complained about archive to download of being virus or menacy.
Would you be so kind directin me to proper source of wp8025ro software download link?
It was also mentioned in manual that possible power supply voltage should be within 12-24 V dc range.
My power supply module outputs 28.5 Volts DC when idling(no load value).
Would it be safe to power wp8025 with 28.5 DC?
I also toggled swithches 3,5,7,8 to 'on' of convertor as it was directed on its rear leaving 1,2,4,6 toggled off.
N. Qv.


As I've stated previously, I am by no means an expert on the WP8025ADAM, nor any other Wellpro devices or other manufacturers' I/O modules. I recommend that you contact Wellpro for these specific questions regarding their product.

That being said, I do have a (seemingly more and more unique) capability to read and understand user's manuals and product labeling, so I may be able to offer some suggestions.

Software and user's manuals are available directly from the vendor's (Wellpro) website here (the vendor's website is stated on the first page of the user's manual for the WP8025ADAM):

Note that there is a disclaimer that the software may be flagged as having a virus/malware, so download at your own risk. Also, all of these files are in Chinese. Unfortunately, this is sometimes what you get when you prioriotize low cost when purchasing a device.

Personally, I would prefer use the GitHub page instead, but this is just my opinion and you should make your own decision from where you are comfortable downloading documentation and software.

Regarding your power supply, according to your image, it is a 27.6V DC (1.3A) power supply. The WP8025ADAM User's Manual states the following under the Specification section:
External power supply DC9V~30V/5W
Since 27.6V is within 9V - 30V and 27.6 * 1.3 = 35.88W is greater than 5W, your power supply should be adequate for powering the WP8025ADAM.

For the toggle switches on your converter, please refer to my post #82. You state 3,5,7,8 are on and and 1,2,4,6 are off. However your image seems to show 3,4,7,8 on and 1,2,5,6 off (which does match both the text on the converter and my post #82).

One other thing I noticed in your image is that you have connected your RS-485 wires incorrectly. You currently have the wires connected to the WP8025ADAM's Relay output channel 5 (RY5A and RY5B). You should connect these wires to the 485A and 485B terminals on the WP8025ADAM.
Dear sir,
As you kindly indexed me I cleared miswiring, and correctly re-toggled switches as mentioned in post #92.
Then I downloaded module software from shwellpro.com\download.
Copied the software, launched it and powered the module.
The module led is on, lighting green constantly.
My issue is driver for the converter.
The converter is unoperable unless driver correctly installed.
Please kindly have a look at the pictures I attached.

I obtained 'hardware IDs' for the usb convertor, and I've been seeking for the proper driver.
Can you kindly direct me onwards any trusted location to obtain driver downloaded?

N. Qv.
According to the Vendor ID and Product ID in your images for your USB to serial converter (found using this website https://devicehunt.com/view/type/usb/vendor/1A86/device/7523), it seems your converter is using the QinHeng Electronics CH340 USB chip.

I believe this is the manufacturer's download for the USB driver:

Again, though, this was just found doing a Google search, so standard disclaimers apply, i.e. I don't endorse or in anyway imply or guarantee this is valid/correct and you are downloading it at your own risk.
Dear jschulze,
I followed your directions on obtaining driver.
It was succesfully installed on my computer, and thus some moments later I was pleased to see my wp8025 relay output module coils trippin' upon commands issued from the wellpro configuration software!
Please kindly have a look at the pics I attached to this post.
driver install manual.JPG
driver installed.JPG
module data read.JPG
port opened.JPG
prior to send.JPG
written to registers.JPG

To be complete this is the link to the video concerning module interaction with the convertor, PC and debugging software I uploaded today onto google disk:


Please kindly have it watched.


N. Qv.
Great! I'm glad you got it working.

The next step is to move on to using a Modbus master tool, such as Modbus Poll or ModScan to read/write Coils 1 - 8 and confirm each relay is responding accordingly. This should work without issues, as the debug tool you are currently using is simply sending Modbus requests to the relay module.
Dear jschulze,
Today I commenced dealing with ModbusPoll referred to WP8025.
Modbus Poll succeded establishing connection with it.
Though my intentions to make its coils trip upon writing into registers did not work.
It is clearly mentioned in the manual how to write multiple coils or single coils, but it didn't make my mindset enough to deal with objective.
Please kindly have a look at the pics below:
The led on the module lights green constantly even though command is send, but sometimes lights red also, witnessing the command was incorrect.
Can you kindly tell me, what did I make wrong?
N. Qv.
Dear jschulze,
I inputed "1" into the span of cells from 0 to 7, it worked flawless!
Thank Goodness!
Then respectively I inputed "0" it released!
The coils are being trip-release upon input change.
Please see the screnshot below:
Modbus Poll Impact to WP8025.JPG

Please have the video watched I shot today concerning Modbus Poll interaction with WP8025 on link below:


N. Qv.