# Weintek cMT2078x Modbus Addressing Help **URL:** \ **Category:** Ignition\ **Tags:** ignition81\ **Created:** [October 18, 2023, 2:45pm UTC](https://forum.inductiveautomation.com/t/weintek-cmt2078x-modbus-addressing-help/80649 "2023-10-18T14:45:46Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![dkhayes117](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/dkhayes117/32/68344_2.png) [@dkhayes117](https://forum.inductiveautomation.com/u/dkhayes117)\ **Post date:** [October 18, 2023, 2:45pm UTC](https://forum.inductiveautomation.com/t/weintek-cmt2078x-modbus-addressing-help/80649/1 "2023-10-18T14:45:47Z")
I've got a new machine in the plant that I'm trying to get Modbus TCP setup on. The OEM sent me some information on the setup, for example ```auto READ 100 RECORDS STARTING FROM 400 ReadValues = modbusClient.ReadInputRegisters(400, 100) MACHINE STATUS REGISTER 400 -> 1=RUN 2=STOP ``` Based on a Weintek PDF I found online input registers are `3x`, so my Ignition OPC tag path is `ns=1;s=[Silo A]3x400` which gives me a bad quality. What am I missing? ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/9/5/956f8a54eddb8e409ea27bb2d2ab6d507c6246a8.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:** [October 18, 2023, 2:51pm UTC](https://forum.inductiveautomation.com/t/weintek-cmt2078x-modbus-addressing-help/80649/2 "2023-10-18T14:51:28Z")
> [@dkhayes117](#): > > so my Ignition OPC tag path is `ns=1;s=[Silo A]3x400` which gives me a bad quality. What am I missing? If that's the literal address you're using you missed the part where you read the Ignition user manual to understand the Modbus address syntax. `3x400` is not a valid address. It would maybe be something like `[Silo A]IR400`. [https://docs.inductiveautomation.com/display/DOC81/Modbus+Addressing#ModbusAddressing-ModbusSpecificAddressing](https://docs.inductiveautomation.com/display/DOC81/Modbus+Addressing#ModbusAddressing-ModbusSpecificAddressing) ---
**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:** [October 18, 2023, 3:26pm UTC](https://forum.inductiveautomation.com/t/weintek-cmt2078x-modbus-addressing-help/80649/3 "2023-10-18T15:26:33Z")
Weintek has gone out on a limb defining non-existent address types. There's no such thing as a 5x address, though the functionality described can be configured on an Ignition driver. The protocol spec has a totally different definition for 6x addresses, with dedicated function codes. ---
**Author:** ![dkhayes117](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/dkhayes117/32/68344_2.png) [@dkhayes117](https://forum.inductiveautomation.com/u/dkhayes117)\ **Post date:** [October 18, 2023, 3:33pm UTC](https://forum.inductiveautomation.com/t/weintek-cmt2078x-modbus-addressing-help/80649/4 "2023-10-18T15:33:43Z")
> [@Kevin.Herron](#): > > If that's the literal address you're using you missed the part where you read the Ignition user manual to understand the Modbus address syntax. `3x400` is not a valid address. I read the manual first. I took it that 3x was the prefix, and using the device address mapping tool generated the `ns=1;s=[Silo A]3x400`, which I see is wrong now. 3x just means the 30000 range. I tried the manual address of `[Silo A]IR400` but it didn't work. ---
**Author:** ![dkhayes117](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/dkhayes117/32/68344_2.png) [@dkhayes117](https://forum.inductiveautomation.com/u/dkhayes117)\ **Post date:** [October 18, 2023, 6:17pm UTC](https://forum.inductiveautomation.com/t/weintek-cmt2078x-modbus-addressing-help/80649/5 "2023-10-18T18:17:36Z")
I figured it out 🙂 I was able to _hack_ the admin password into the Weintek HMI. With easybuilder pro, I downloaded the project from the HMI, and decompiled it. They had the Modbus unit id set to 1 where I was trying to use unit id 0. ---
**Author:** ![dkhayes117](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/dkhayes117/32/68344_2.png) [@dkhayes117](https://forum.inductiveautomation.com/u/dkhayes117)\ **Post date:** [October 18, 2023, 7:57pm UTC](https://forum.inductiveautomation.com/t/weintek-cmt2078x-modbus-addressing-help/80649/6 "2023-10-18T19:57:45Z")
@Kevin.Herron Seems I need a little help on string conversion. IR480-499 are being read as 16int. I set up a tag with path `[Silo A]1.HRS480:20` - Without any string handling options I get an empty string. - With reverse byte order, I get **Z** - With read raw string checked, I get **Z Pillow 4** - Change path to `[Silo A]1.HRS480:40`, I get **Z Pillow 43OZCAC`** The manual says that each word is 2 characters, but best I can tell I only have one char per word. ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/6/f/6f415c8111a72b51fbfb690b8e79e9d765baea09.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:** [October 18, 2023, 8:01pm UTC](https://forum.inductiveautomation.com/t/weintek-cmt2078x-modbus-addressing-help/80649/7 "2023-10-18T20:01:26Z")
What string are you expecting? You may have some trouble here, the Modbus driver doesn't so Strings in any kind of sane manner. ---
**Author:** ![dkhayes117](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/dkhayes117/32/68344_2.png) [@dkhayes117](https://forum.inductiveautomation.com/u/dkhayes117)\ **Post date:** [October 18, 2023, 8:03pm UTC](https://forum.inductiveautomation.com/t/weintek-cmt2078x-modbus-addressing-help/80649/8 "2023-10-18T20:03:32Z")
Sorry, I meant to include that in the last post `Z Pillow 43 OZ` is the correct value ---
**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:** [October 18, 2023, 8:09pm UTC](https://forum.inductiveautomation.com/t/weintek-cmt2078x-modbus-addressing-help/80649/9 "2023-10-18T20:09:44Z")
`[Silo A]1.HRS480:40` is probably closest to what you want. This means read 40 bytes, aka 20 registers. The string either has to be fixed width or null terminated. edit: if you're expecting null-terminated, make sure the raw strings option is false. ---
**Author:** ![dkhayes117](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/dkhayes117/32/68344_2.png) [@dkhayes117](https://forum.inductiveautomation.com/u/dkhayes117)\ **Post date:** [October 18, 2023, 8:20pm UTC](https://forum.inductiveautomation.com/t/weintek-cmt2078x-modbus-addressing-help/80649/10 "2023-10-18T20:20:10Z")
I think it is null terminated, 0 in ascii should be null; therefore the null would be `RecipeName15` hmm, I reloaded the recipe name on the HMI, and it started acting completely different. I had to reverse the byte order and then uncheck the raw string option and it worked as expected 🤷‍♂️ ---
**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:** [October 18, 2023, 8:23pm UTC](https://forum.inductiveautomation.com/t/weintek-cmt2078x-modbus-addressing-help/80649/11 "2023-10-18T20:23:13Z")
> [@dkhayes117](#): > > it started acting completely different Eww. That suggests that different parts of its code do strings differently. ---
**Author:** ![dkhayes117](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/dkhayes117/32/68344_2.png) [@dkhayes117](https://forum.inductiveautomation.com/u/dkhayes117)\ **Post date:** [October 18, 2023, 8:31pm UTC](https://forum.inductiveautomation.com/t/weintek-cmt2078x-modbus-addressing-help/80649/12 "2023-10-18T20:31:00Z")
Weird, with `HRS480:40` the string must be **over** 20 chars long for it to read correctly. If I do 20 chars or less, it only shows the very first character in the string. So weird.