# Modbus TCP Packet Data **URL:** \ **Category:** Ignition\ **Created:** [January 31, 2020, 12:42am UTC](https://forum.inductiveautomation.com/t/modbus-tcp-packet-data/31809 "2020-01-31T00:42:39Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![qasemalmansuri](https://avatars.discourse-cdn.com/v4/letter/q/ecd19e/32.png) [@qasemalmansuri](https://forum.inductiveautomation.com/u/qasemalmansuri)\ **Post date:** [January 31, 2020, 12:42am UTC](https://forum.inductiveautomation.com/t/modbus-tcp-packet-data/31809/1 "2020-01-31T00:42:39Z")
Hi, I have this data from master computer commining over ethernet cable: 00 03 00 80 00 01 84 33 Is there anyone there to describe details of the above stream? Thanks ---
**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:** [January 31, 2020, 12:45am UTC](https://forum.inductiveautomation.com/t/modbus-tcp-packet-data/31809/2 "2020-01-31T00:45:25Z")
Looks like: ```auto 00 unit/slave id 03 function code (Read Holding Registers) 00 80 address (128 decimal) 00 01 quantity (1 decimal) 84 33 checksum ``` and despite coming over ethernet it looks like it’s just an RTU frame. There’s no MBAP header as there should be on ethernet. ---
**Author:** ![qasemalmansuri](https://avatars.discourse-cdn.com/v4/letter/q/ecd19e/32.png) [@qasemalmansuri](https://forum.inductiveautomation.com/u/qasemalmansuri)\ **Post date:** [January 31, 2020, 1:09am UTC](https://forum.inductiveautomation.com/t/modbus-tcp-packet-data/31809/3 "2020-01-31T01:09:13Z")
Thank you for your reply. This is the type of data as shown on the Modbus 32 simulator However having used another simulation software called Modbus poll and the data is more detailed with extra info i.e. header as following: 00 00 00 06 00 03 00 08 00 01 84 33 Any suggestion? in particular would you agree that the unit ID = ‘0’ ---
**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:** [January 31, 2020, 1:40am UTC](https://forum.inductiveautomation.com/t/modbus-tcp-packet-data/31809/4 "2020-01-31T01:40:28Z")
I don’t know what the extra data is in those bytes. The MBAP header for TCP is 7 bytes.