Invalid Cell Temperatures (LTC6813-1 daisy-chain)

[niktwo17]

Hi foxBMS-Team,

I have an issue with reading the cell temperatures from the slave (configuration: 6x LTC6813-1).

• I receive correct cell voltages and other data for all 6 modules of the daisy chain
• However, (correct) cell temperatures are only received for the first 3 modules. Module 4 and 5 show values of -128 (via CAN) or -17219 via debugger from ltcData->cellTemperature, module 6 shows 0 consistently
• The issue is NOT existent when I manually disconnect the daisy-chain and treat module 4-6 as modules 1-3 separately, then I get correct temperature readings
• The RDCOMM gives me 0b0111 (Slave Ack) for module 1 and 0b1111 (Slave Not Ack) for modules 2-6.
• I have tested the issue with unmodified releases 1.6.0 and 1.7.0 My assumption based on this would be some kind of timing-inconsistency for the daisy-chain based communication with the slaves, have you encountered a similar problem or can give some further recommendations?

Thank you, Niklas

[foxBMS]

Dear @niktwo17,

thanks for the report. We will have a loot at and come back once we have more information.

Best regards, The foxBMS Team