PowerLogic T500 – TI=46 Double Command rejected; DO works only via web Force

[OdysseiaTiTi]

Hi all,

I’m running an PowerLogic T500 (HU280 + DI180 + DO180) with Easergy Builder v1.7.49 as an IEC-104 slave (ASDU addr = 1, port 2404).

What works

• Telemetry is fine: analogs and double-point DIs come through over 104.

• From the web UI, Force DO works — relays click, so hardware is OK.

The issue

• From an IEC-104 tester, sending TI=46 (C_DC_NA_1 / Double Command) does not operate the DOs.

• In the trace I see COT=6 (activation) followed by “7: negative activation confirmation” (no termination). The relay doesn’t move.

What I’ve tried

• 104 Enable = ON.

• CMD use act term = ON, CSE use act term = ON.

• In Control Points, C_DC is enabled; tried both Direct Execute and Select→Execute (SBO).

• In coreDB → Command, IOAs 160–167: CDC are mapped to DO180 channels (Latch = N, ExeTim = 500 ms).

Question

• Is there any T500-specific setting or trick required to make TI=46 Double Command drive the DOs?

• If the T500 expects particular QOC/QU/Select bit combinations, could you share a working example frame?

• Also, is there a global Secure / Block controls option that might be rejecting C_DC commands?

Thanks a lot! 🙏

[Araceli_Monje]

Hi @JuanRayo , could you please help @OdysseiaTiTi with these questions about T500?, thx.

[JuanRayo]

Hello @OdysseiaTiTi .

There is no trick at all. 

Please share with us your Easergy Builder configuration and some wireshark traces captured when the command failed.

BR

[JuanRayo]

Sorry for the delay , I do not know why this topic did not reach our inbox sooner.

[OdysseiaTiTi · Accepted solution]

Hi all,

Just a quick update to close the thread — I’ve finally identified the cause and the issue is now resolved.

The problem was related to the Select Before Operate (SBO) mode. The IEC-60870-5-104 tester I was using had “SBO mode” enabled, and at the same time, the “Select before operate” checkbox in Easergy Builder (under output configuration) was also checked.

At first, I thought that checkbox only affected specific 104 output modes, but when I hovered over it, the tooltip clearly described it as the Select Before Operate feature. Once I disabled this option, the DOs successfully operated when commanded from the 104 tester. With the option enabled, the relays didn’t respond.

Later, I tried a different 104 tester and found that it worked even in SBO mode — so the behavior actually depends on the tester implementation.

Thanks everyone for your input and comments. Hopefully this helps others who encounter the same situation.

 

[JuanRayo]

Thanks for your feedback on behalf of the community..