# Modbus TCP or Allend Bradley EthernetIP? **URL:** \ **Category:** Ignition\ **Created:** [February 20, 2013, 12:21am UTC](https://forum.inductiveautomation.com/t/modbus-tcp-or-allend-bradley-ethernetip/5899 "2013-02-20T00:21:54Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![techerdone](https://avatars.discourse-cdn.com/v4/letter/t/9fc348/32.png) [@techerdone](https://forum.inductiveautomation.com/u/techerdone)\ **Post date:** [February 20, 2013, 12:21am UTC](https://forum.inductiveautomation.com/t/modbus-tcp-or-allend-bradley-ethernetip/5899/1 "2013-02-20T00:21:54Z")
In most cases I would go for the OPC-UA support of the AB EthernetIP device but I am wondering if anyone can suggest why it would be better to use one or the other? Speed? Efficiency? Reliability? ---
**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:** [February 20, 2013, 12:50am UTC](https://forum.inductiveautomation.com/t/modbus-tcp-or-allend-bradley-ethernetip/5899/2 "2013-02-20T00:50:39Z")
What device are you connecting to? It’s usually better to go with the device’s “native” protocol. ---
**Author:** ![Dravik](https://avatars.discourse-cdn.com/v4/letter/d/e274bd/32.png) [@Dravik](https://forum.inductiveautomation.com/u/Dravik)\ **Post date:** [February 20, 2013, 12:51am UTC](https://forum.inductiveautomation.com/t/modbus-tcp-or-allend-bradley-ethernetip/5899/3 "2013-02-20T00:51:38Z")
Interoperability. LOTS of things are capable of talking Modbus TCP. EthernetIP is great with devices that talk it though! ---
**Author:** ![techerdone](https://avatars.discourse-cdn.com/v4/letter/t/9fc348/32.png) [@techerdone](https://forum.inductiveautomation.com/u/techerdone)\ **Post date:** [February 21, 2013, 9:50pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-or-allend-bradley-ethernetip/5899/4 "2013-02-21T21:50:13Z")
Micrologix 1400 will be used. I agree with both of you just trying to see if there was any documented evidence for one over the other. Like write/read time, number of messages to accomplish the same task, etc. Thanks. ---
**Author:** ![diat150](https://avatars.discourse-cdn.com/v4/letter/d/a587f6/32.png) [@diat150](https://forum.inductiveautomation.com/u/diat150)\ **Post date:** [February 21, 2013, 10:20pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-or-allend-bradley-ethernetip/5899/5 "2013-02-21T22:20:45Z")
[quote=“techerdone”]Micrologix 1400 will be used. I agree with both of you just trying to see if there was any documented evidence for one over the other. Like write/read time, number of messages to accomplish the same task, etc. Thanks.[/quote] well, if I remember correctly, if you use modbus tcp on the 1400 you will have to pack all of your values into the data files that you tell the channel configuration to use for each respective modbus code. so in that respect, you may have to do more programming work. I believe you can do both at the same time also, ethernet/ip and modbus tcp on the same 1400. ---
**Author:** ![Kakkerlak](https://avatars.discourse-cdn.com/v4/letter/k/bb73d2/32.png) [@Kakkerlak](https://forum.inductiveautomation.com/u/Kakkerlak)\ **Post date:** [February 26, 2013, 3:11pm UTC](https://forum.inductiveautomation.com/t/modbus-tcp-or-allend-bradley-ethernetip/5899/6 "2013-02-26T15:11:35Z")
I would just use the native protocol of the A-B controller. Because the MicroLogix 1400 uses the classic A-B style “typed data tables” it’s just as efficient as Modbus/TCP. Organize your Ignition data into dedicated data tables (one for Integers, one for REALs, one for Strings, etc) and you’ll get the best results. As mentioned above, you can run both the native EtherNet/IP protocol and one other protocol simultaneously on the MicroLogix 1400 Ethernet port; you choose either DNP3.0 or Modbus/TCP. ---
**Author:** ![techerdone](https://avatars.discourse-cdn.com/v4/letter/t/9fc348/32.png) [@techerdone](https://forum.inductiveautomation.com/u/techerdone)\ **Post date:** [April 6, 2013, 2:51am UTC](https://forum.inductiveautomation.com/t/modbus-tcp-or-allend-bradley-ethernetip/5899/7 "2013-04-06T02:51:35Z")
Just thought I’d mention that the limitation I have found with Modbus TCP for the micrologix is that you are limited to only binary and integer data types. No floats or longs! Also, there is a 5 data file limit for the holding registers. So 1280 ints in holding registers. Binary has a 4096 limit for either type of binary modbus register.