问题
We have EP300 device working in server mode. I've implemented Anviz Client application in PHP language in accordance with this protocol description.
I have noticed some unexpected stuff in a handler for Get record information (0x3C) command: from time to time, with expected response (with ACK 0xBC), I'm receiving additional lines like this: a500000001df00000e000000000a259a2b6501030000001bd9.
Here is complete "parsed" example of such response:
STX | CH | ACK | RET | LEN | DATA | CRC16
--- | -------- | --- | --- | ---- | ------------------------------------ | ---
a5 | 00000001 | bc | 00 | 0012 | 00002600002a000002000000004e2c000003 | 0cc0
a5 | 00000001 | df | 00 | 000e | 000000000a259a2b650103000000 | 1bd9
As I found in documentation, df ACK code is returned for Sent T&A record in real time CMD：0x5F. Not sure how it works but looks like it sends TA records in response of other commands. The DATA structure is the same as for Download T&A records CMD：0x40 command
User code | Date&time | Backup code | Record type | Work types
---------- | --------- | ----------- | ----------- | ----------
000000000a | 259a2b65 | 01 | 03 | 000000
It makes me confused a bit and it is unexpected and I'm afraid it may cause some TA records lose. I suspect that after TA records are sent with "real time" response, they will not appear next time in response for "Download T&A records" command when I'm trying to fetch new TA records.
Can anyone advice with it:
- How to properly handle "Sent T&A record in real time" items and "Download T&A records" together?
- May be "Sent T&A record in real time" can be switched off?
Thanks
来源：https://stackoverflow.com/questions/59528983/anviz-ep300-unexpected-data-in-response-of-get-record-information-command-0x3c