EML Handshake is a defined data formatting handshake that allows the
Voyager RF to send and receive data from the Host System through the Base
Station.
To be able to use this feature, the Base Station:
• Must be connected via RS232 to the Host System using the M-01
cable
• Must have EML feature activated (see Base Station’s manual to know
how to activate EML into Base Station as well as EML Packets
description).
EML Handshaking Process
When EML is active, every time a Voyager RF reads a barcode, the Base
Station will send “Data Packets” to Host (via Wedge or RS232) so that the Host
will know which Base Station and Voyager RF is sending data.
Furthermore, the system provides a way to inform the Voyager RF whether its
data was found in Data Base by activating EML Handshake within the Base
Station. The process is as follows:
The Voyager RF sends data to Base Station and a “WAIT” radio command is
sent from Base to Voyager RF. After that, Base sends the “Data packet” to the
Host and waits for “EML Command” from Host. When this has been received,
Base acknowledges it with “ACK Packet” and transfers it to Voyager RF which
performs the corresponding action.
If Host Delays its answer, Voyager will timeout and will consider an error in
transmission, informing the Base Station that timeout (1 – 17 sec) has elapsed.
Base will send “RESET Packet” to Host to inform of this situation and will
answer with a “NAK Packet” to every command coming from Host until a new
“Data Packet” is received from the Voyager RF.
The possible Voyager RF timeout values must be between 1 – 255 in steps of
70 msec. This will give us a range of 1 to 17 sec. By default is 2 Sec.
EML HANDSHAKING TIMEOUT
MS9530 Voyager RF Printed: September 2002
Version: 1.1 Status: Approved
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