1747-SN Configuration

Hello everyone,

I need dire help for my PLC assignment, i'm trying to configure 1747-SN RIO scanner. The Comms light is blinking red. I checked my cables and made sure its functional.


The project contains 6 neumatic actuators, all with advance and retract features. All the air lines and presasure regulators are already set up, I am just building the program, connecting to the PLC, and creating an HMI panelview interface.

I am having some trouble connecting to the plc, this is the equipment I am using:

SLC 5/05
1747-L551 (Slot 1)
1746-NT4 Analog 4 Ch Thermocoupe Input (Slot 1)
1746-NI4 Analog 4 Channel Input Module (Slot 2)
1746-NO4I Analog 4 Ch. Current Output (Slot 3)
1746-IB16 16 Input (SINK) 24VDC (Slot 4)
1746-OW16 16 Output (RLY) 240 VAC
1747-SN RIO Scanner (Slot 6)


This is what I am trying to connect to:


1794-ASB RIO Adapter
1794-0A8 Flex I/O x 2 (output)
1794-IB16 Flex I/O (sink input)

The picture i've attached is my G-File configuration. Can someone please lead me in the right direction and kindly assist me if I am missing anything. Thank you.

how do you have the DIP switches set on the 1794-ASB? ...

also, what series (A, B, etc.) is your 1794-ASB? ...

Ron's questions are right on; the 1794-ASB DIP switch settings can be slightly different depending on the Series letter. The last and most common Series was the 1794-ASB Series E.

You're going to want to set up the 1794-ASB for Rack 00, at 230.4 kb/s, and Single Slot Addressing. That will make each physical module take up one 16-bit word of Input data and one 16-bit word of Output data.

You generally have a 50/50 shot at getting the blue and clear insulated wires of the Belden RIO cable in the right order; it can't hurt to reverse them to check.

Ron, the DIP switch is both set to off as Ken said, so I can get a 230.4 kb/s baud rate.

The series is series B.

Also, does the baud rate on the 1747-SN RIO Scanner have to match the same baud rate on the 1784-ASB? Right now it's at 57.6kb/s. So should I change it to 230.4kb/s? I have it set at Rack 00

With that being said, is my G-File configuration accurate?

Thank You.

Should I keep M0 and M1 to default settings?

Sorry for disturbing but I still couldn't get it to communicate with eachother

Yes, you need to have the data rate set the same on both the scanner and the adapter. There is no "auto-sensing" sort of feature with RIO devices.

The G-file is correct for a 1794-ASB set up in the most common single-slot mode.

The two OA8 modules will be the first "1/4 Rack" and the one IB16 module will be the first word of the next "1/4 Rack", so the total size will be 1/2 Rack.

The addressing will be:

1794-0A8 O:6.0
1794-0A8 O:6.1
1794-IB16 I:6.2

Thanks a lot!! I got a green active light and green communications light! Everything seems to be working fine, but I got one issue.

One of the output modules (1794-0A8) terminal base isn't working. I tested to see if there is voltage/current going through which there is, even tried swapping the two output modules with each other and the module in the second terminal base still worked in the first one.

Which leaves me to believe maybe its the configuration with the dip switches and what not. I tried playing around with the DIP switches to mess with it and see why the output module wasn't working.

Any suggestions?