What is Devicenet? in allen bradley

backendcode

Member
Join Date
Aug 2017
Location
brampton
Posts
249
Hello Everyone, I am trying to find some article and watching a youtube video to understand the concept of DeviceNet and can't find enough information. Can someone share any article or your knowledge on this subject?

Please correct me if I am wrong, So far I know DeviceNet is

a communication module can be installed in any slot of PLC rack and the main purpose of this communication module is to connect a PLC controller to remote IO so wiring cost can be reduced.

For example, If I am using one PLC processor to control two production line and these two production lines are far from each other and I don't want to use long wiring to connect devices on production line such as push button, sensors etc back to my IO card of PLC controller, then i can use deviceNet module and install remote IO close to 2nd prodcution line and connect those remote IO with processor through DeviceNet and in that case I will only need one communication cable between devicenet and remote IO and field devices on 2nd production line will connect to my remote IO.

in that case, The remote I/O will be slave and PLC controller will be Master and DeviceNet is the medium which helps PLC controller to send a signal to remote IO.

Please correct me if I get so far right. Now I have a couple of question on that.

1. When I install DeviceNet module to my PLC rack, what kind device/hardware do I need to connect with my Remote IO? or am I going to connect that DeviceNet module directly to remote IO?

2. Let's say If I have more than 2 remote IO at a different location. Do I need 2 DeviceNet module? 1 for each remote IO?

3. How many remote I/O I can connect with my DeviceNet Module?

I am asking this question because let's say I am using processor which allow me to connect maximum of 4 module, instead of using 4 I/O module, Can I connect 4 devicenet module and then connect 4 I/O module to each devicenet so this will allow me to connect 16 remote I/O module.

I would really appreciate if someone can help me to figure this out.


Thank you for reading this post,

Thank you,
 
I don't know a huge amount about devicenet, but your understanding so far is correct.

1. You will need a devicenet scanner module at your PLC, and then a devicenet remote I/O module. Connecting them you will need proper devicenet cable, with proper devicenet resistors at each end of the "trunk", and a certified devicenet power supply powering the network.

2. Devicenet is a "drop" style network, in that you can "drop" to multiple devices. So no, you will only need one devicenet scanner at your PLC, and then your devicenet cabling will "daisy chain" to each of your remote I/O modules

3. Devicenet has a maxiumum of 64 addresses (0-63). I'm not 100% sure if all of these are usable addresses or which ones might be reserved for certain things. I *think* that address 0 is reserved for a programming terminal, but I'm really not certain.
 
let's say I am using processor which allow me to connect maximum of 4 module,

Hold on for a bit.

Are you talking about an SLC-500 family controller equipped with a Remote I/O Scanner module, like the 1747-SN ?

In that context, "Remote I/O" is the Allen-Bradley Universal Remote I/O Protocol, which is proprietary and runs on a characteristic twin-conductor blue-jacketed cable.


In general, a 1747-SDN DeviceNet scanner takes the place of a 1747-SN RIO scanner, allowing you to use DeviceNet media and I/O blocks and devices to connect to the scanner.

The I/O data capacity, flexibility, and speed of DeviceNet is much larger and faster than RIO.

But you need to follow more complex wiring guidelines, and you need to be willing to put in the effort to learn how to connect to, configure, and maintain the network devices. You also need a license for RSNetworx for DeviceNet software, and a computer->network connection device. Both are moderately expensive if you are not already using DeviceNet.
 
I don't know a huge amount about devicenet, but your understanding so far is correct.

1. You will need a devicenet scanner module at your PLC, and then a devicenet remote I/O module. Connecting them you will need proper devicenet cable, with proper devicenet resistors at each end of the "trunk", and a certified devicenet power supply powering the network.

2. Devicenet is a "drop" style network, in that you can "drop" to multiple devices. So no, you will only need one devicenet scanner at your PLC, and then your devicenet cabling will "daisy chain" to each of your remote I/O modules

3. Devicenet has a maxiumum of 64 addresses (0-63). I'm not 100% sure if all of these are usable addresses or which ones might be reserved for certain things. I *think* that address 0 is reserved for a programming terminal, but I'm really not certain.
Thank you for the reply and make some points clear to me.

Thank you,
 
Hold on for a bit.

Are you talking about an SLC-500 family controller equipped with a Remote I/O Scanner module, like the 1747-SN ?

In that context, "Remote I/O" is the Allen-Bradley Universal Remote I/O Protocol, which is proprietary and runs on a characteristic twin-conductor blue-jacketed cable.


In general, a 1747-SDN DeviceNet scanner takes the place of a 1747-SN RIO scanner, allowing you to use DeviceNet media and I/O blocks and devices to connect to the scanner.

The I/O data capacity, flexibility, and speed of DeviceNet is much larger and faster than RIO.

But you need to follow more complex wiring guidelines, and you need to be willing to put in the effort to learn how to connect to, configure, and maintain the network devices. You also need a license for RSNetworx for DeviceNet software, and a computer->network connection device. Both are moderately expensive if you are not already using DeviceNet.

Hey I am talking about compact and control logix family and I have all the software on my work laptop. I started working as a junior control engineer so I was trying to clear my concept of DeviceNet and other communication protocols.

Thank you for the response

thank you,
 

Similar Topics

Hello all, is it possible to reset a faulted armor block thru the plc? I know I can reset the devicenet card, and some devices thru the PLC, but...
Replies
4
Views
1,435
Needing RS Logix 5 programming examples for communicating (PLC 5/40E) to multiple Ultra 100 servo drives over devicenet. The user manual for the...
Replies
0
Views
1,289
I'm trying to commission a DeviceNet network between a 1756-DNB scanner card and a Toyopuc DLNK-S2 DeviceNet card. I see both the scanner and...
Replies
7
Views
3,305
Hi, I'm not very experienced on Allen Bradley and i'm trying to solve an error 78 showing on a 1747-SND. The PLC is a SLC 5/05CPU. the error...
Replies
1
Views
8,644
I am sending Omron Text over devicenet to an AB GuardLogix Processor. I am having a difficult time converting the string to readable data. I am...
Replies
8
Views
4,107
Back
Top Bottom