FastSyncRead can read data from 2 dynamixels, but not from additional dynamixels


(What Arduino Compatible Microcontroller are you using?)

currently working on OpenCR1.0

Software Description

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Example fast_sync_read in Dynamixel2Arduino edited for 4 Dynamixels which have ID from 1 to 4

Issue Description

(A detailed description of the issue you are experiencing, along with any error messages or other information you may have. The more information you share the more likely it is that somebody can help)

Trying to read current positions from my four Dynamixels with FastSyncRead command.
From the example, I have made only two changes and they are DXL_ID_CNT = 4 and DXL_ID_LIST[DXL_ID_CNT] = {1, 2, 3, 4}.
I can read datas from ID 1 and 2 but not from 3 and 4.
If I change the order of IDs, e. g. DXL_ID_LIST[DXL_ID_CNT]={3, 4, 1, 2}, I can read datas from ID 3 and 4 but not from 1 and 2.
Anyone knows why this happens?

When I sent FastSyncRead command with Dynamixel Wizard 2.0, I could see that status packet is correct.
Maybe some kind of translation in Arduino is wrong?

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