Devicenet Scanner card

Hi,

I am trying Devicenet communication between SLC 500 (1747-SDN module) & Indramat PPC motion controller. I am getting error code 77 on Devicenet scanner display. I checked the the data size in Scan list & motion controller data and it seems to be matching. The other thing I observed was that when I double click on Scanner card in RS NetWorx and go to Summary tab it shows Scanner card in Slave Mode & not active. Is this OK? I checked back in Scanner configuration and I have not selected Slave mode.

Does anybody has seen similar problem?

Just a thought, have you programmed the scanner card run bit in your plc logic to be set to a one? If not the scanner card will be in idle mode. Check the status bits for the scanner.


regards

kevin

[Cracks knuckles] Oh boy, Error 77 !

First, sweep aside that Slave Mode issue. the Scanner can be simultaneously a master and a slave (to another master) and you just haven't enabled that function.

Error 77 means that the size of the I/O connection configured in the Scanner is not the same as the I/O connection size reported by the slave during connection establishment.

This is pretty common with devices that have variable I/O sizes, especially when the I/O size depends on several different parameters, or on some slightly obscure configuration inside the device.

There is a foolproof way of determining what the Slave device thinks it's I/O size should be. Right-click on the motion controller icon in the graphical network view in RSNetworx for DeviceNet and select the Class Instance Editor.

Using the default "Get Attribute Single" service, enter the following object values and hit the "Execute" button.

Class 5, Instance 2, Attribute 7 = Produced Data Size

Class 5, Instance 2, Attribute 8 = Consumed Data Size

Class 5 is the "Connection" object, and Instance 2 is the Polled I/O connection. For COS/Cyclic connections, it's Instance 4.

Data Produced by the Slave is Input data to the SLC.
Data Consumed by the Slave is Output data from the SLC.

Configure the I/O connection size in the Scanner configuration (the Edit I/O Parameters button on the Scanlist tab) to match those values you got from the message tool above, cycle power to everything, and your Error 77 should disappear.

Let us know how it works

Google, I am thinking of getting one of those 1747 SDN modules for motion applications. I am very interested in how well it works.

To Kevin: Yes, The Run bit is already set.

To Ken : I tried what you suggested but it shows a message " Timeout during a request to address 2" (address 2 is motion controller)in Data recevied from the device window. Does it mean the communication link between scanner & motion controller is not eastablished ? I checked 24 V DC power supply & 121 ohm resistor and they are OK. Is there anything else that you can suggest.

Thanks for your response.

Well, the timeout means what it says; the software did not get a response from the Indramat controller.

Three things to try:

1. Check that terminating resistor value again; there should be two 121 ohm resistors (either extreme end of the trunkline), giving a resistance of 60.5 ohms or so between the blue and white wires.

2. Remove the 1747-SDN from the network, then cycle power and try sending the message to the Indramat controller. To make sure communications works, try executing the "Get Attribute Single" message with Class 1, Instance 1, Attribute 1 (Vendor ID), or doing the RSWho function, which does the same thing. This might not work, because the Indramat controller may not consider the I/O connection configured until the 1747-SDN requests it to be configured (which we prevented by removing it from the network).

What I'm thinking is that maybe the Indramat can only make one Explicit Message Connection, and it can't talk to the RSNetworx software when the 1747-SDN has it's Explicit Message Connection open trying to set up the I/O connection and check it's size and keying.

3. Try using the 1747-SDNPT Passthrough driver instead of a 1770-KFD or 1784-PCD. The 1747-SDN will be the originator of all of the messages, not the KFD/PCD, so there's just the one messaging connection open. I'm less sure about the efficacy of this method.

As a last resort, start trying variations in the I/O size configuration and see if you can guess it.

(p.s. I'm curious about the Indramat controller; can you e-mail it's EDS file to the address in my profile ? I'm on a customer site near Beaverton, OR this week but I'd like to see this anyhow.)

Now my devicenet is working well. The problem was that motion controller has to be in a particular mode to respond on devicenet. Earlier it was not but now its working. The other problem was that the no. of bytes in motion controller was not matching with scanner scan list. That was also fixed.

Thanks for everybody's help.

Indramat PPC FDS

Could someone please send me a FDS file for an Indramat PPC? I need it ASAP.