1747-SN RIO discreet Transfer

[John Doherty 0]

Im adding additional I/Os to an existing panel. For the additional I/Os I have them on a remote chassis connected to 1747-asb remote adapter which is communicating with a 1747-sn scanner on the primary chassis in the 12th slot with a SLC 5/03. On the remote chassis I have 6 I/O cards: 2 Digital input cards (1746-IA16), 1 Analog Input card (1746-NI8), 1 Analog Thermocouple (1746-NT4), 1 Digital Output card (1746-OW16), and 1 Analog Output card (1746-NO41) . Overall I have 19 data words to transfer over and Im using no complimentary I/0. Ive set up the adv configuration and G file of the 1747-sn as so: adv config.bmp G file.bmp I want use RIO discreet transfer instead of block transfer and Im rather new at this and have no clue how to do this or represent this in my coding. Any help would be much appreciated?

[Ken Roach 194]

The G-file configuration (essentially the Scan List of the 1747-SN) will only make sense if we know what other devices are on the network and which Rack Number you've set this "remote chassis" to. The 1746-NI8 is the issue; you can't run them in Discrete Mode. They require Block Transfers. So your decision is whether or not to attempt to use the 4-channel analog modules in Discrete mode or not. I personally wouldn't: Three or four Block Transfers aren't a whole lot more complicated than one. Do you have a 1747-SN Series B scanner, which supports Block Transfers ? Does your SLC-5/03 firmware support Block Transfer instructions (about the last 7 years worth do) ? Are there other devices on the RIO network, or just this one remote Chassis ?

[John Doherty 0]

Well the scanner is going to be on rack 12 so i assume thats what the slc is reading the remote chassis from rack 12. This is the only remote chassis ill be using and on the remote chassis the I/O cards will be in order as how i listed them with the adapter in slot 0. Yea both the scanner and the slc 5/03 support block transfer. So yea i guess Ill use the block transfer for the analog signals and discreet for digital. You wouldnt have any or know of any examples of code online that I could look at and see as first hand example? Im just not sure how to even start assigning addresses and incorporating it in my code.

[Ken Roach 194]

The basic idea is to think of the 1747-SN as a big I/O module. I usually leave the Input and Output sizes at 32 words each. Then think of the discrete "Scanlist" you configure using the G-File setup as a 32-word data table divided up into four 8-word blocks. In RIO terms, these 8-word blocks are "Logical Racks" numbered 0, 1, 2, 3. Let's say you set up your 1747-ASB adapter as Rack 00, and it's in a 1747-A7 chassis. In "1-Slot" Addressing mode, each module gets 1 word of data, so 6 modules = 3/4 of an 8-word "Rack". In the G-File, configure only Rack 00, and set it up as "3/4 Rack" size. Your discrete I/O gets mapped like this: I:12.0 1746-IA16 Input Data I:12.1 1746-IA16 Input Data I:12.2 1746-NI8 (no discrete data) I:12.3 1746-NT4 (no discrete data) I:12.4 1746-OW16 (no discrete Input data) I:12.5 1746-NO4I (no discrete data) O:12.0 1746-IA16 (no discrete Output Data) O:12.1 1746-IA16 (no discrete Output Data) O:12.2 1746-NI8 (no discrete data) O:12.3 1746-NT4 (no discrete data) O:12.4 1746-OW16 Output Data O:12.5 1746-NO4I (no discrete data) When you address your Block Transfer instructions, the "Rack/Group/Slot" addresses for the analog modules are: 1746-NI8 Rack 00, Group 2, Slot 0 1746-NT4 Rack 00, Group 3, Slot 0 1746-NO4I Rack 00, Group 5, Slot 0 There are good examples of Block Transfers for most modules in the RA Knowledgebase. Get the simple NT4 and NO4I modules working first, then tackle the more complicated NI8.