Filter
Top Products
-
3. Control command for decoder chip
Important: This chapter describes low level command for scanner control function. If you
already USI to do scanner programming, you don’t need to care about this chapter. In general, it
is not suggested to use level command to control scanner, because there are timing issue on
serial communication programming , and it is always need communication expert to do that and
it is hard to explain it on document.
When Host prepare to send a command to hamster, it must first check CTS, if CTS is high, then
Host must set the RTS to high then clear RTS to low to wake up the Hamster.
Special Command for control
command Format Comment
Control Esc,80H+SOH(01H) Let Hamster enter slaving status. At this status Hamster just
receives commands and executes it until it receives Release
command or timeout (about 10s). Otherwise, the timeout is
about 1s as the interval of commands.
Release Esc,80H+EOT(04H) Let Hamster exit from slaving status.
Execute/
Enquiry
Esc,80H+ENQ(05H) Let Hamster execute the previous saved command and check
hamster if there is a result of previous executed command to
send to Host. If previous saved command have already
executed and no result to send, hamster do not reply until
there is a result. If Host receive a result but the BCC is wrong,
it can re-send ENQ to re-send result again.
ACK Esc,80H+ACK(06H) It is from Hamster to Host. If Hamster receive a command and
this command do not need send message back, Hamster reply
the ACK.
NAK Esc,80H+NAK(15H) It is from Hamster to Host. Hamster require the Host to re-send
command again, normally when received a wrong BCC, it can
send the NAK. The Hamster sends back NAK whenever it
receives a no sense command.
COMMAND FROM HOST TO HMASTER
Command format:Esc,Lh,Ll,n,m,S1,...,Si,BCC
Here: Esc is Escape code(H'1B)
Lh/Ll is command's length when the Lh.b7 is 0, Lh is high byte, Ll is low byte, count from n to BCC.
When Lh.b7=1 it is a two bytes special command.
n is command ID
m is operation: Normally for setting commands the 0 means setting, 1 default, 2 read current setting, 3
special operation. When m=1 or 2, the S1 should be 0 for bits or one character setting. If the setting is a
string, like pre_amble, the read or default command should not contain any Si byte. The special meaning
in a command please refers the command definition.
Si is setting/read data.
BCC: it equals to XOR of all the bytes before the BCC.
Conventions: S1.bj means the number j bit of byte S1.
The expression 1~64:2 means that the number is between 1 and 64, the default is 2.
Notice: Any interval in a command transmit can not exceed 1 second.
Command Format Comment
Initial/ Warm
start
Esc,0,2,0,BCC Hamster initializes the ports and flags according to the setting
in RAM.
Default Esc,0,2,1,BCC Reset setting in RAM and initialize
Mpu_idle Esc,0,4,2,m,S1,BCC S1 is 0~3:0 is sleep mode,1 is watch mode,