Panelview 550 with DH+ or Remote I/O

[mulderm 3]

Hello, Can anyone tell me what the different is between a panelview 550 using DH+ or using Remote I/O. How is the communication with this difference with a PLC5? Greetings, mulderm

[korted123 0]

If you have the choice, use DH+. Both DH+ and remote IO are possible from a PLC5, but remote IO is more cumbersome than DH+. DH+ allows bidirectional communication at the same address - the PLC can change N7:0 and the operator can see that it changed, and the operator can change N7:0 and the PLC will see that the operator changed it. This scenario is not possible with remote IO. Remote IO is not necessarily bad, but it will take you longer to develop the same functionality.

[Jnelson 0]

Here are two assumptions correct me if I'm wrong. RIO uses user defined block transfers in the plc to read and write data to and from a device. Data Highway + uses asychronous communications meaning that the plc can send and recieve data just as the panelview can send and recieve data simultaneously. I am just starting to learn this too, so these are more of a question than an answer. Thanks John

[Contr_Conn 4]

My opinion: Use RIO for HMI only as a last resort, you will dramatically limit you HMI functionality and increase programming time if you use RIO. DH+ is way to go. PLC normally has 2 channels, so use DH+ if you already have RIO.

[Guest Guest]

The RIO method CAN use block transfers but they are not required. By the nature of RIO the Panelview appears to the PLC as a standard I/O rack. You can select the size. If you choose full rack, there are eight each input and output words available to use for sending or receiving bits or words. If only a few words and bits are needed you can do something like: MOV C5:0.ACC I:3.0 or XIC I:3.1/2 to read a bit from the PV. Then, in the Panelview to display the value of C5:0 you'd create an object using I:3.0 as the input word. Don't quote me word for word on this but it's pretty close to how it's done. If there are going to be a lot of values or ASCII strings exchanged, then yes, you'll need to roll out the block transfers.