Help understanding data frame

[pwntester]

I got this message correctly interpreted as flowtempdesired = 17.0:

2025-06-18 21:59:11.133 [update notice] sent poll-read hc Flowtempdesired QQ=31: 17.0
2025-06-18 21:59:11.133 [bus notice] >31085022030002009e<0002a90100c3>00

I tried to understand the frame:

• QQ = 31
• ZZ = 08
• PBSB = 0522
• NN = 03
• DD = 000200
• CRC = 9e
• ACK = 00
• RESP NN = 02
• RESP DD = a901
• ????? = 00 <-- this should not be here if length is 02
• RESP CRC = 03
• ACK = 00

a901 -> 01a9 = 425 in decimal. The divisor used for other flowtempdesired is 10. However, in this case, it seems the divisor is 25 (425/25=17.0). Any ideas why ebusd used a different divisor from the one specified in the CSV? May it has to do with that extra 00 byte?

Thanks!