Simply Modbus logo





RTU Master

RTU Slave

TCP Client






Count me as simply delighted with Simply Modbus.

Having used another Windows based Modbus master in the past for field testing Modbus installations with all sorts of Modbus slaves and several different HMIs as masters, I find Simply Modbus has several features that gives it boost in performance for my purposes.


1) Simply Modbus has the capability to designate the word format for each register address. In applications where word formats are mixed, for instance, where status words use an integer format, and analog data uses floating point, the other program required the use of multiple windows because each window had only one designated word format.
With Simply Modbus, it's possible to view any given register address in any given word format. So status and analog data appear in the same view (contiguously addressed in the slave).

2) I simply love the notes column, which makes it easy to describe the register's contents and include things like engineering units descriptors. When things aren't quite right and there's 10 or even 20 registers showing, who can remember which is which and what the expected value is? I know I can't. I spend a minute spent describing the contents of the registers and then I can tell whether the value showing for 40013 is what it should be or not.

3) The serial communications parameters are immediately evident, being right there on the screen. For instance, on those startups where the comm link balks, where parity is a likely suspect, it's so easy to not only see which setting is in use, but to change it to another setting.

4) Likewise, turn around settings, the RTS delay and timeout, are displayed right there and easy to change.  It's easy to bump the settings.

5) I like the one shot poll mode, with the option for continuous polling. When things don't work, taking a one-shot poll provides the data for some thinking-cap head-scratching needed to solve the problem, without the distraction and "noise" of continuous updates and error codes.

6) I suspect any Modbus master tool provides the actual hex code somewhere, but Simply Modbus puts it right there on the left.

7) There's a check box for the dreaded "offset" and the a text box for the starting address for the offset. The register addressing can remain the same while only the offset gets changed. Nice.

8) The four float combinations of Little Endian/Big Endian and byte order are doable with the high byte/low byte and high word/low word check boxes.

9) The write button brings up a new window with all the settings needed to write.
Very clean. Full request and response hex codes as well.

I was stymied on my first attempt at using Simply Modbus to read correct values. But I got a quick response to my email request for help with a couple screen shot attachments.
The response was a suggestion that nailed the problem with one setting change
(offset, duh . . . like I shouldn't have gone there first).
Now that's service for a shareware priced app! ! !

Those of us who have to get Modbus links running know how poor the documentation is for many slave devices. With a tool like Simply Modbus, it's easy to experiment on the various parameters. Recently I checked the manufacturer's documentation to see which data format his product uses and there was no mention of data format, only an address map. Some things are obvious from a map, and some aren't. When I called tech support for this (slave) device, I heard "Oh yeah, Modbus. I think that's RS-432, right?" I knew it was up to me to figure it out on my own. And I did, in about 2 minutes with Simply Modbus.

In the past, I had suffered for some time with only a demo version of a low end HMI for testing Modbus, and thought I'd really moved upscale with the other Modbus Master tool. Simply Modbus is now my tool of choice. I gladly paid its modest license fee for its great performance and ease-of-use. Simply Modbus is simply a bargain, a super package for the price. The publisher even offers the convenience of paying for it through PayPal!

I am eager to check the TCP version.

Dan Weise
Lesman Instrument Co.
Bensenville, ILL

Home FAQ Enron Download Purchase Contact

Copyright © 2015 Simply Modbus. All rights reserved