next command, the Encompass 4 Reader will not service the new command; it will
retransmit its previous message. A command/message sequence is not complete until
the host updates its sequence number.
<cmd>
Command code, a string that contains from two to four ASCII hex characters
[<data>
]
Optional data field, an ASCII string of as many as 20 characters in length. For example,
the store hardware configuration string command is
#696S...S
or command
#696
Store Hardware Configuration
String followed by the data string
S...S
.
<crc>
CRC value for the message
<eom>
End-of-message character (ASCII CR)
Reader Command Response
The basic protocol format is
<som><resp><eom>
The ECP format is
<som><seq><resp><crc><eom>
where
<
som
>
Start-of-message (ASCII # character)
<
seq
>
Echo of sequence number received in host command message
<resp>
Response string. The Encompass 4 Reader returns
Done
,
Error
, or another ASCII
string depending on the host transmission. This string can be up to 72 characters long.
<crc>
CRC value for the message
<eom>
End-of-message character (ASCII CR and LF)
Sample Messages
This section contains examples of typical messages transmitted between the Encompass 4 Reader and
the host computer.
Reader Transmissions
Basic protocol reader transmission
#KING 1302<eom>
Host response:
No host response for non-ECP
ECP reader transmission
#4KING 1302 <crc><eom>
where
#
Start-of-message character
Encompass 4 Reader System Guide
TransCore Proprietary.
6–76
Summary of Contents for encompass 4
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