# TSI AeroTrak 7510 using Modbus TCP Driver **URL:** \ **Category:** Ignition\ **Tags:** ignition81\ **Created:** [November 20, 2023, 8:13pm UTC](https://forum.inductiveautomation.com/t/tsi-aerotrak-7510-using-modbus-tcp-driver/82158 "2023-11-20T20:13:15Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![Travis.Dreier](https://avatars.discourse-cdn.com/v4/letter/t/e9bcb4/32.png) [@Travis.Dreier](https://forum.inductiveautomation.com/u/Travis.Dreier)\ **Post date:** [November 20, 2023, 8:13pm UTC](https://forum.inductiveautomation.com/t/tsi-aerotrak-7510-using-modbus-tcp-driver/82158/1 "2023-11-20T20:13:15Z")
I am trying to communicate with an TSI AeroTrak 7510 using the Modbus TCP driver. Not sure what makes this device different than other Modbus devices I have communicated with but I realized that I needed to pick a unique Modbus Unit ID for each address I am reading why would this matter with Modbus TCP? Any idea what makes this device require use of the Modbus Unit ID feature? ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/1/4/14235f3e40f40d73dbcf69ea9e2b42ffb1236698.png) ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [November 20, 2023, 8:20pm UTC](https://forum.inductiveautomation.com/t/tsi-aerotrak-7510-using-modbus-tcp-driver/82158/2 "2023-11-20T20:20:01Z")
Got any docs for this device? What happens when you don't use different unit ID per address? Have you connected any other Modbus software to see what happens (modpoll, etc...)? ---
**Author:** ![Travis.Dreier](https://avatars.discourse-cdn.com/v4/letter/t/e9bcb4/32.png) [@Travis.Dreier](https://forum.inductiveautomation.com/u/Travis.Dreier)\ **Post date:** [November 20, 2023, 8:52pm UTC](https://forum.inductiveautomation.com/t/tsi-aerotrak-7510-using-modbus-tcp-driver/82158/3 "2023-11-20T20:52:08Z")
[AeroTrak\_Remotes\_Modbus\_Reference\_5001430C.pdf](https://forum.inductiveautomation.com/uploads/short-url/esnQcwGOEd6cbOG5J8awDspWpC4.pdf) (699.4 KB) See attached Modbus address reference. We have a few of these talking through a Prosoft Gateway and don't need to reference Unit ID. One other observation is that it seem like the ignition TCP driver honors some security that the other Modbus devices don't. I can't write to an address until I login using the web page interface of the device. This is a problem because the manual explains that I need to login over modus to enable writes but I can't write to the registers that it wants me to write the password to. The Prosoft device does not require login or password to write over Modbus from what I can tell. ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [November 20, 2023, 8:54pm UTC](https://forum.inductiveautomation.com/t/tsi-aerotrak-7510-using-modbus-tcp-driver/82158/4 "2023-11-20T20:54:34Z")
Maybe you can use Wireshark or a managed switch packet capture to compare the difference. There's nothing weird going on with the Ignition Modbus driver. ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [November 20, 2023, 8:56pm UTC](https://forum.inductiveautomation.com/t/tsi-aerotrak-7510-using-modbus-tcp-driver/82158/5 "2023-11-20T20:56:24Z")
Supports modbus function codes 3 and 6 _only_. ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [November 20, 2023, 9:00pm UTC](https://forum.inductiveautomation.com/t/tsi-aerotrak-7510-using-modbus-tcp-driver/82158/6 "2023-11-20T21:00:55Z")
Given this, you'd want to un-check the "Allow Write Multiple Registers Request" advanced setting. ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [November 20, 2023, 9:05pm UTC](https://forum.inductiveautomation.com/t/tsi-aerotrak-7510-using-modbus-tcp-driver/82158/7 "2023-11-20T21:05:55Z")
This is a bit of a mystery: > Read Circular Buffer Data > The circular buffer stores records in the 32 byte record buffer format, and is located at registers > 40225 - 88225. Each record is 16 registers long so the first record is located at 40225 - 40240, and > the last record is located at 88209 – 88225. Modbus registers max out at 65535... ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [November 20, 2023, 9:07pm UTC](https://forum.inductiveautomation.com/t/tsi-aerotrak-7510-using-modbus-tcp-driver/82158/8 "2023-11-20T21:07:49Z")
I'm guessing some clueless software engineer doesn't understand that the `4` is a prefix, and thinks 40000 is simply a base address. 🤷‍♂️ ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [November 20, 2023, 9:09pm UTC](https://forum.inductiveautomation.com/t/tsi-aerotrak-7510-using-modbus-tcp-driver/82158/9 "2023-11-20T21:09:31Z")
Infinite monkeys... ---
**Author:** ![Travis.Dreier](https://avatars.discourse-cdn.com/v4/letter/t/e9bcb4/32.png) [@Travis.Dreier](https://forum.inductiveautomation.com/u/Travis.Dreier)\ **Post date:** [November 20, 2023, 9:53pm UTC](https://forum.inductiveautomation.com/t/tsi-aerotrak-7510-using-modbus-tcp-driver/82158/10 "2023-11-20T21:53:43Z")
Well I unchecked the Allow Write Multiple Register Request I can now write the register I need to without login. I still for some reason need to pick a unique Unit ID for each register I want to read/write to but it is working so I am moving on. Thanks Kevin/Phil ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [November 20, 2023, 10:01pm UTC](https://forum.inductiveautomation.com/t/tsi-aerotrak-7510-using-modbus-tcp-driver/82158/11 "2023-11-20T22:01:46Z")
> [@Travis.Dreier](#): > > I still for some reason need to pick a unique Unit ID for each register I want to read/write to Maybe because the "Span Gaps" setting (enabled by default) is combining them into a request for a range the device objects to, and by adding unique unit id you prevent that from happening. You're lucky this device just ignores unit id if that's it. ---
**Author:** ![Travis.Dreier](https://avatars.discourse-cdn.com/v4/letter/t/e9bcb4/32.png) [@Travis.Dreier](https://forum.inductiveautomation.com/u/Travis.Dreier)\ **Post date:** [November 20, 2023, 10:19pm UTC](https://forum.inductiveautomation.com/t/tsi-aerotrak-7510-using-modbus-tcp-driver/82158/12 "2023-11-20T22:19:48Z")
@Kevin.Herron disabling the span gaps allowed me to remove the Unit ID's Thanks