Reverse Engineering/Help with RS232 protocol on a Qiagen Tissuelyser II - Page 1
Forum section: electronics / projects

author: MFraylich
author_rank: Newbie
timestamp: January 30, 2019, 12:44:36 pm
content: This is a very specific question, but I will accept a more general answer if it helps me with the process of reverse engineering it. If you happen to be a Qiagen engineer and are willing to give me the protocol that would save me a lot of time and effort.I need to connect to the machine to set times, speeds and start the machine automatically. Qiagen technical support does not or will not release information on the protocol, or they don't actually know.Finding the correct baud rate and connecting to the device shouldn't be an issue, though it is a popular machine and I haven't been able to sit down with it yet. The issue as far as I see it is working out what commands to give to instruct the machine to do what I want.As far as I know, the only people who interact with the RS232 are service engineers and QC testers, so I don't have access to any hardware that puts out these commands to just read it off.It is very possible I am the first person with the need to interface with this machine outside of their engineers.Does anyone have any idea where to start with this? I am missing a trick somewhere?Thank you for at least reading my question.

author: jeremy
author_rank: Super Contributor
timestamp: January 30, 2019, 01:01:56 pm
content: Are you sure that the commands which you need exist?Can you get anything at all to talk to it so that you can observe the communication?

author: MFraylich
author_rank: Newbie
timestamp: January 30, 2019, 01:13:13 pm
content: Truthfully I know nothing about it except it has an RS232 port on the back and they would need to test the completed machines off the assembly line. If I were making them I would use that port, rather than leaving them open or having a person program and test them. In addition, the technical support guy did believe that service engineers use it.My alternative is to open it up and insert wires to basically pretend to be the buttons on the top and then drill a hole to get them out and connect to whatever I might use in the final design (perhaps a pi for the interface) and I would prefer not to drill a near $13000 piece of machinery if at all possible.

author: jeremy
author_rank: Super Contributor
timestamp: January 30, 2019, 01:25:39 pm
content: For a low volume, high price device, I don’t think it would be unreasonable to test each unit by hand. Depending on the age of the design and how precise these machines need to be, there could be potentiometers, set screws, etc that need adjusting while the machine is in some sort of calibration test jig. This may need to happen well after assembly because sometimes devices sit in storage and nobody wants to get a cal cert which is 3 years old! Serial port may just be for firmware upgrades.If you can’t observe any communication, it might be hard to get anywhere. And if you aren’t able to open it, you may find that the 9 pin D connector has non standard wiring (it certainly wouldn’t be the first expensive life sciences instrument to do that).I think your only real option given the constraints is to send random garbage in the pin you think is RX, listen on TX and hope that you get something useful.

author: MFraylich
author_rank: Newbie
timestamp: January 30, 2019, 01:41:54 pm
content: I have seen a few that have non-standard wiring, but they weren't labeled as RS-232. I am crossing my fingers that it follows some sort of standard. I can open the machine, but I prefer not to. Not just because of warranty issues and the like, but because it is in constant use and opening it will affect other peoples schedules.I always strive for the most elegant solution where possible as well and if I can use the RS232 it is much more scaleable if we need to automate more in the future, and would always prefer to waste a week down a non-destructive line of thought before I move on.Thank you for your input though.