In the TRM, it said the 0x2B command allows the host to control the FETs of the BMS, but I never succeed. I can access other command except this one, actually I can read the command 0x2B, but I cannot control it. I follow the two steps as described in the TRM.
1. Send FET Control Access Code [0x1197] to HostFETControl().
2. Send data to turn on or off the required FET to HostFETControl() within 4 s of sending the FET Control
Access Code.
My understanding is that I need to write twice with word protocol. The first write is 0x1197 with command 0x2B and the second write is FET states data with command 0x2B, am I right?
During my testing, I also found a strange thing that the BIT description of command 0x2B is different from pratical testing. When the PCHG is on, the read data of 0x2B is 0x04, but in the TRM the PCHG is BIT3, which should be 0x08. Also for the CHG FET and DSG FET, the read data is 0x01 and 0x02, which means it should be in BIT0 and BIT1. Is it the mistake of the TRM?
BTW, to control the FETs, should I use the MAC command 0x001E, 0x001F, 0x0020? Which method do you suggest?