NX1P2 explicit messaging

[Pascaljt]

Hello,

I try to have a communication between a device in Ethernet/IP with my NX1P2.

I use the CIP_Open block before the CIP_Send block but I have an error 1C05, "connection not established". However my communication is ok because I can drive my device in implicit messaging. My IP address is ok. I don't understand.

Somebody can help me please ?

Pascal.

[IO_Rack]

I prefer to use the CIPUCMMSend instruction. It does not require the CIPOpen.

What device are you communicating with?

[Pascaljt]

Hello IO_Rack,

Thanks to answer to my request.

I use a controller for electrical actuator (JXC91 from SMC) in Ethernet/IP. I thought that the CIPUCMM instruction was to communicate between 2 PLC.

I'm going to try tomorrow morning (I'm in France). What is the difference between CIPUCMM and CIPSend ?

Thanks for your help.

Pascal

[IO_Rack]

3 hours ago, Pascaljt said:

What is the difference between CIPUCMM and CIPSend ?

I'm not sure honestly. From the Omron Ethernet manual, it states CIPSend is for Class 3 connection method and CIPUCMMSend is for UCMM (Unconnected Message Manager) connection method. I don't know EtherNet/IP in such detail.

It's possible it may not work for you. I couldn't find explicit messaging functions for the JXC91. Is this a separate manual?

I have used the CIPUCMMSend instruction for slave devices that support it.

Edited July 20, 2020 by IO_Rack

[Crossbow]

CIPOpen, close read write uses EtherNet/IP Class 3 communication, which requires a connection be established first.

UCMM is UnConnected Message manager, a different EtherNet/IP protocol that does not require a connection (as the name implies).

They are both defined in the EtherNet/IP specifications.  Some devices only work one way or the other.

[Pascaljt]

Hello Crossbow and IO Rack,

Many thanks for your answers.

As I'm connected with my Omron I must use the CIP Send.

The CIP_Open function block is ok but I have an error 1C00 "explicit message error" with my function CIP_Send. I can't solve this problem however I'm sure that the instance, class and attribute be right. I don't understand.

I keep looking, I never give up

Pascal.

 

[Pascaljt]

On 21/07/2020 at 11:22 PM, Crossbow said:

CIPOpen, close read write uses EtherNet/IP Class 3 communication, which requires a connection be established first.

UCMM is UnConnected Message manager, a different EtherNet/IP protocol that does not require a connection (as the name implies).

They are both defined in the EtherNet/IP specifications.  Some devices only work one way or the other.

Hello Crossbow,

It's ok, I tried to use the function block UCMM Send and use my device unconnected. That's works perfectly. I'm surprise because the explicit messaging should work connected and unconnected. Maybe that the device don't be Ethernet class 3. I must learn more information about that.

Have you some links interesting to help me ?

Thanks in advance.

Pascal.

 

[Pascaljt]

On 20/07/2020 at 10:01 PM, IO_Rack said:

I'm not sure honestly. From the Omron Ethernet manual, it states CIPSend is for Class 3 connection method and CIPUCMMSend is for UCMM (Unconnected Message Manager) connection method. I don't know EtherNet/IP in such detail.

It's possible it may not work for you. I couldn't find explicit messaging functions for the JXC91. Is this a separate manual?

I have used the CIPUCMMSend instruction for slave devices that support it.

Hello IO Rack,

I succeed to communicate with this block. It's ok.

thanks again

[IO_Rack]

You are welcome. Thanks for posting your results!

Implicit messaging is simple enough. I've had moderate success doing explicit messaging for a well documented client. I wish I had more in depth knowledge of the Ethernet/IP standard to be able to troubleshoot problems easily.

[Crossbow]

Now with Class 3, there are two methods to open a connection.  Your device may not support one of them.  CIPOpen uses what's called "Large Forward Open", if your device does not support Large Forward Open method, you can use the CIPOpenWithDataSize function block which can be used to perform normal "Forward Open".