Rice Lake Motorola DS457 Laser Scanner - Manual (Page 91)

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Programming a Multicode Expression via SSI Command
The following example describes how to program a Multicode expression via SSI within a Remote Scanner
Management (RSM) command.
SSI Transaction Sequences
Before sending the Multicode expression transaction (a command/response pair), perform the following
initialization transaction (command and response). This initialization transaction is required only once upon
each imager power up:
Command (to imager): 0A 80 04 00 00 06 20 00 00 FF FE 4D
Response (from imager): 0C 80 00 00 00 08 20 00 00 F0 00 F0 FD 6C
Next, program the Multicode Expression using the following basic transaction format.
Command (to imager): 17 80 04 00 00 13 06 00 02 95 41 00 42 00 06 00 [Multicode Expression in
Hex] FD A3
Response (from imager):
08 80 00 00 00 04 06 00 FF 6E
For full details on structuring Multicode expression commands, see
Figure 6-4
.
Legend for Figure 6-4
•
All values in the table are hex, unless followed by a
d
which indicates decimal.
• Shaded fields represent values that change for different Multicode expressions.
Unshaded fields are fixed and are constant for all expressions.
• N
: The length of the Multicode expression in bytes. Using
Example 1
,
N
= 6 decimal, 0x06 hex.
• Len1
: N+17. Using
Example 1
,
Len1
= 23 decimal, 0x17 hex.
• Len2
: N+13. Using
Example 1
,
Len2
= 19 decimal, 0x13 hex.
• Op
: Command persistence.
•
0x06 stores the Multicode expression in non-volatile memory. The command persists through power
cycling.
or
•
0x05 stores the Multicode expression in RAM. The command is lost when power is removed from the
imager.
• Len4
: Same value as
N
. Using
Example 1
,
Len4
= 6 decimal, 0x06 hex.
• Checksum
: 2's compliment checksum of bytes in the SSI Header and SSI Data. Sum all bytes, truncate
to a 2 byte value, subtract this value from 0x10000; the resulting number is the 2 byte checksum. Using
Example 1
the checksum is
FDA3
.