ML 15000 with 1769 SDN devicenet scanner.
Using 4 EC3+, want to send PLC output via device net to one of the EC3+ outputs to turn on a pilot light and or the EC3+ starter
Question:

When I look at the output table, I see 4 words, one for each EC3+, labeled as 1769-SDN device net scanner
How do I tell which bit goes with one of the two ouputs (A or B) in the EC3+?

The addressing inside the MicroLogix depends on how the data is mapped in RSNetworx for DeviceNet.

The first two words of the 1769-SDN output data table are reserved for module commands. So the Output data map begins at O:1.2 (assuming the scanner is in expansion slot 1).

Each E3+ overload relay maps just 1 byte of data from the 1769-SDN to the overload relay. You can pack these bytes two-to-a-word, or you can put each one on its own word boundary. The default is to pack them byte-by-byte. This is done in RSNetworx for DeviceNet software.

If you have all the defaults set up, your E3+ overload outputs will be addressed:

O:1.2/0 Overload Relay#1 Output A
O:1.2/1 Overload Relay#1 Output B
O:1.2/2 Overload Relay#1 Trip Reset

O:1.2/8 Overload Relay#2 Output A
O:1.2/9 Overload Relay#2 Output B
O:1.2/10 Overload Relay#2 Trip Reset

O:1.3/0 Overload Relay#3 Output A
O:1.3/1 Overload Relay#3 Output B
O:1.3/2 Overload Relay#3 Trip Reset

O:1.3/8 Overload Relay#4 Output A
O:1.3/9 Overload Relay#4 Output B
O:1.3/10 Overload Relay#4 Trip Reset

Thanks I've read all the documentation and I don't recall that explaination!

If you have a minute, can you lay out how the inputs (from EC3+) are mapped to the ML1500?

That's another "it depends", and it's more complicated.

The default Input Assembly that is produced by the E3/E3+ and consumed by the controller consists of 4 words of data, which are configured in Parameters 61, 62, 63, 64 of the E3/E3+.

The default parameters that are produced by the E3/E3+ are Parameters 21 (Status), 1, 2, 3 (Phase A, B,C current in Amperes).

I like to change the parameters that are produced by the E3/E3+. My typical configuration is Parameter 21 (Status), Parameter 8 (3-phase Average % of Full Load Amperes), Parameter 9 (% Thermal Utilization) and Parameter 15 (Warning bits).

These four words will be mapped into the MicroLogix 1500 memory table starting with word 66 for the 1769-SDN slot. The first 66 words (0 through 65) are the Status image for the module.

Yes, it can be confusing to have your first Input bit be at I:1.66/0 and your first Output bit be at O:1.2/0. But that's the way the 1769-SDN works with the MicroLogix 1500, and once you start labeling input data you'll be OK.

The default configuration and mapping will yield (assuming the 1769-SDN in Slot 1)

I:1.66 Overload Relay #1 Status
I:1.67 Overload Relay #1 Phase A Current in Amperes
I:1.68 Overload Relay #1 Phase B Current in Amperes
I:1.69 Overload Relay #1 Phase C Current in Amperes

I:1.70 Overload Relay #2 Status
I:1.71 Overload Relay #2 Phase A Current in Amperes
I:1.72 Overload Relay #2 Phase B Current in Amperes
I:1.73 Overload Relay #2 Phase C Current in Amperes

I:1.74 Overload Relay #3 Status
I:1.75 Overload Relay #3 Phase A Current in Amperes
I:1.76 Overload Relay #3 Phase B Current in Amperes
I:1.77 Overload Relay #3 Phase C Current in Amperes

Addendum: if you put a zero into any of the parameters that point to the Input Assembly members (Parameters 61, 62, 63, 64) then the assembly size will be truncated to the number of parameters before the zero. That way you can get just 2 or 3 feedback parameters if your I/O table is crowded.