Thanks.

4121be35-62ae-4676-ae3e-b162cab49b68-image.png

The term "injection" is normally used with data bytes; for RTS/DTR, it simply means "setting the state of the line".

Serial Tap Pro is a next-generation serial sniffer; the functional differences that distinguish it from the original Serial Tap (https://ioninja.com/hardware/serial-tap.html) are as follows.

Serial Tap Pro features:

Read more at the product page: https://ioninja.com/hardware/serial-tap-pro.html

Could you please share an .njlog or at least a screenshot of communications? That would help to choose the best approach.

Have questions or comments? Leave them here!

It doesn't dive into the internals of parsing Modbus RTU frames themselves, but you'll be able to enumerate and extract all Modbus RTU master and slave frames from your .njlog file -- and take it from there.

https://ioninja.com/blog/welcome-to-io-ninja-blog/

Feel free to use this forum thread for comments & discussion.

Thank you for your feedback, I really appreciate it!

We released Serial Tap Pro two months ago, and a new revision for Ethernet Tap (Ethernet Tap Pro?) is our next goal! At the very least, it should include Gigabit Ehternet support, automatic port speed selection, optional packet injection (which could be disabled at hardware level via jumpers -- just like in Serial Tap Pro), guarantee of non-disrupting the original link in case of power loss, high-precision (at least 1 microsecond) hardware timestamps, optional enclosure -- and more (hopefully, Automotive Etherent, too). We are still in the research & design stage, so there's no strict release date set -- sorry about that. As soon as we have a more definitive timeline, we will definitely post an update on this!

I've replied to this request over email, but let's cover it here, too -- in case anyone else bumps into a similar problem.

Support for Serial Tap Pro was added recently, in IO Ninja 5.8.0 -- therefore, please make sure that you are on a version higher than this. Generally speaking, you always want to be running the latest and greatest version of IO Ninja.

Also, on Windows, for Serial Tap Pro and other hardware sniffers to function correctly, the official hardware driver is required. This driver is actually nothing more than a manifest telling Windows to use the system winusb.sys for devices with our VID/PIDs (vendor and product IDs). Nevertheless, this step is essential -- without it, IO Ninja won't be able to communicate with the taps (and taps will have an exclamation mark in Windows Device Manager).

If you install IO Ninja via the "FULL" MSI installer, those drivers should be installed automatically. Otherwise (e.g., you prefer a portable .7z archive), please download drivers separately at Download -> IO Ninja Hardware Drivers; install them either (a) using dpinst64/dpinst32 or (b) through the standard Update Driver process in Device Manager.

After driver installation completes successfully, the taps in Device Manager should show no exclamation mark and use winusb.sys as a kernel-mode driver.

db0ff6d0-24b7-47dc-990b-5c09dc0cc709-image.png

Could you please share the .inf file for this driver? Or better yet, can you provide a download link for this virtual serial port driver so that we can play with it locally?

However, the your script is not a valid Jancy script.

A simple echo script looks something like this:

Of course, you can modify the reply packet before transmission as you like, e.g.:

You can also try our stock scripts ("Load stock script" in the drop-down next to the "Open" button on the Script pane) -- they can be used as a starting point for something more meaningful.

Also, check in-app scripting tutorials here:

https://ioninja.com/doc/developer-manual/tutorials.html

Apologies for the delayed response.

You are 100% correct -- the hostname resolver should respect the IPv4 address when present. IPv6 should not be required when IPv4 is available.

Actually, the logic here is a bit more complex -- all socket-based plugins can optionally bind to local IPv4 or IPv6 adapters. So, when this binding is in place, the hostname resolver should choose the corresponding address family and ignore everything else.

We'll add this for the upcoming release in June. I'll share a link to the internal build after we have it done if you wish to try it before the official release.

However, there's no out-of-the-box integration with data acquisition services.

If it's the monitor-and-analyze part you are interested in, then the roadmap is as follows.

The first stage is to acquire the TCP conversation between Modbus Master and Modbus Slave. In IO Ninja, this can be done via two alternative approaches.

(a) You can capture Ethernet packets using Ethernet Tap or Pcap Sniffer (capturing via Pcap could require some trickery if the Modbus Master is not running on the same workstation as IO Ninja), then reconstruct TCP conversation by attaching TCP Flow Analyzer.

(b) But a more straightforward approach would be to use IO Ninja as a man-in-the-middle and let it forward TCP traffic between the Master and Slave using TCP Proxy. Whenever this man-in-the-middle approach is applicable (i.e., you are in control of the Master and can redirect it to IO Ninja), that should be your choice -- it's much more straightforward and reliable.

After you set everything up for reconstruction of the raw TCP conversation between Master and Slave, you attach the Modbus Analyzer to decode the raw bytes into human-readable Modbus frames.

IO Ninja log is very powerful and should be more than enough to inspect and analyze the Modbus conversation.

If you need to post-process it further, one option would be to create a Log Layer to do the job (remember, IO Ninja is scriptable!). However, for people who have never touched IO Ninja scripting before, a much more straightforward path would be to save the log as .njlog and use any scripting language of their choice to walk over it.

The .njlog file format is very simple and all the relevant data structures & constants are open-source and defined in scripts/api/log_RecordCode.jnc and scripts/api/log_RecordFile.jnc (included in IO Ninja packages).

Hope this helps; feel free to follow up with any questions!

capture serial communication with up to 3.3mbps

3.3 Mbps is beyond the maximum baud rate supported by Serial Tap. Baud rates <= 1 Mbps are guaranteed to be reliably captured; ~2 Mbps could work in theory, but errors are possible, and I think 3 Mbps would be outright rejected by the UART controller we use in Serial Tap.

add custom protocol parsing logic

This is possible; IO Ninja supports so called "layer" plugins that can transform original logs and add decoded protocol messages. See the Modbus Analyzer for an example of such layer plugin (it's open-source and located at /scripts/plugins/Modbus/)

perform time event measurement

Events are timestamped on the PC side -- the Serial Tap reports raw bytes and status line changes, IO Ninja adds timestamps and writes them to log.

be controlled by Python with ability to get parsed data, set time markers ad get time for each events

If you need to implement custom processing in Python, you can use ioninja-hwc (https://ioninja.com/features/hardware-client.html#cli) -- capture Serial Tap events from the command line and redirect those to a file or stdout; then implement whichever custom logic you need in Python.

Regarding the gauge of the wire, as long as it can be fit to the connector of the Serial Tap, it should be fine. The noise should not depend on the gauge of the wire in such a short length.
Unfortunately, I cannot see your connection to Serial Tap very clearly from your attached image. Generally, many of these errors on RS485 can happen because of impedance mismatch on the line. For example, I am not sure you have termination resistors on the bus or not. If not, you can add one 120Ohm resistor at each end of the bus and see if things get corrected. This is quite important in the long buses.
Another thing to try is to ensure you connect the ground between your board and Serial Tap. I assume you are already using a shielded cable between your board and Serial Tap. Join the GND and shield and connect them to GND pin on Serial Tap. Of course, RS485 does not need the Ground connection but as you are adding a stub to your RS485 bus and we don't know you have proper termination or not, so I offer this to try.
By the way, I recommend taking a look into the following article that we have created for Modbus and RS485 connections:
https://support.tibbo.com/hc/en-us/articles/40709215801369-FAQ-What-are-the-consideration-of-implementing-RS485-example-with-Modbus-sensors