USR-K6 User Manual www.usriot.com
Jinan USR IOT Technology Limited 39 / 107 [email protected]
The frame mechanism of serial port is based on the packaging time and the packaging length.
1.
Serial port packaging time: the default is 4 bytes of send time.
The default package time of K6, the interval that serial port receive time more than 4 bytes packaging time, K6
packaging sending. E.g. baud rate is 115200K time for 4 bytes is 0.4ms, if the value less than 0.1ms, the package time
calculate as 0.1ms. A formula to calculate as fellows:
T
＝
1/baud rate*10*4
2.
Serial port package length: default package length is 400 bytes
When K6 receive data from webpage, and then send to serial port. For the limited of the serial speed, the user
need to control the flow, otherwise data overflow problems can be occur and drop the package. So when send data
from network to serial port, please calculate the flow.
Calculate way: if sending M bytes need N s. the way to check for possible overflow methods (if the net situation is
ok, the time can be ignored ). The time for M bytes:
T
＝
1/baud rate*10*m
If there is no overflow, M bytes of data must be transmit within Ns, then N>2T is require for K6 to work properly.
4.3.3.
RFC2217
Similar RFC2217 is a simple RFC2217 protocol, working with the VCOM and changing serial port parameters
candynamically to realize the communication with variable serial port parameters.
Enable this function, using USR-VCOM can open this function,which can realize the serial baud of the PC software
and K6 automatically match. No need to pay attention to serial port baud rate setting.