Pico & DeviceNet

[devo.xx 0]

Hey guys, I've got an existing system in the field that consists of: 1756-L61 - Main PLC --> 1756-DNB - DeviceNet Scanner A system of 20 Nodes --> 2 Nodes have: ----> 1760-DUB+LDF Pico GFX-70 -------> 1760-DNET Currently, the DeviceNet is set up so that I can see these Pico modules over the network. But, when they were installed, the contractor stopped there... ie. The device exists, but never actually transmitted or received any signals. At the time, that was all that was necessary: Give the operator a numerical feedback on the Screen. Now, I need to Read/Write a "Marker Word" on the Pico module. I have been searching the net now for ... too many hours ... and haven't found a useful manual that actually explains the Communication method. Let alone, how to set up this DeviceNet card for communication! I'm really at a stand-still, and am considering just buying an Analog-In and an Analog-Out card for DeviceNet, then possibly being forced in to purchasing a new Encoder and Proportional valve.... Not ideal. Any help would be great! Thanks

[JRoss 84]

For a start, you'll need the software RSNetworx for Devicenet. Using that you'll be able to modify the settings in the 1756-DNB so that you can add the Picos to the read/write schedule. That's an overly simplistic answer, but should get you pointed in the right direction.

[Ken Roach 194]

When you open up the 1760 DeviceNet interface (it's under the Communications Adapter group, at the bottom) you see that it has a fairly crude I/O connection of just 3 bytes of Input and 3 bytes of Output as a Polled I/O Assembly. Not all bits are used. From the I/O Data information in RSNetworx: Input Assembly: Bit 0 RunStatus Bit 4 Without Input Delay Bit 5 With Input Delay Bit 8 S1 Bit 9 S2 Bit 10 S3 Bit 11 S4 Bit 12 S5 Bit 13 S6 Bit 14 S7 Bit 15 S8 Output Assembly Bits 0-4 Unused Bit 5 Run Bit 6 Stop Bit 8 R9 Bit 9 R10 Bit 10 R11 Bit 11 R12 Bit 12 R13 Bit 13 R14 Bit 14 R15 Bit 15 R16 Bit 16 R1 Bit 17 R2 Bit 18 R3 Bit 19 R4 Bit 20 R5 Bit 21 R6 Bit 22 R7 Bit 23 R8

[Ken Roach 194]

The 1760-DNET User Manual [Direct Link] has the rest of the information you need to compose a DeviceNet Explicit Message that can transfer data other than the S (physical PICO output status) and R (output data used by the PICO as Input data) registers. Do you know the exact data register or tag in the Pico GFX that you need to read or write ?