Ssi Message Formats; Engine Control Commands - Symbol SE955 Integration Manual

10-4 SE955 Integration Guide

SSI Message Formats

The following sections describe each of the SSI messages that can be communicated between the decoder and host. See
Transactions on page 10-27
The messages are separated into two categories:
• Engine Control Commands - Commands that configure and control various scan engine features. These commands are
considered public commands and are available to all hosts. These opcodes are in the range of [0x04 - 0xF6].
• Remote Monitoring Commands - Commands that are used for remote monitoring of the scan engine attributes. These
commands are also considered public commands and are available to all hosts. These opcodes are in the range of
[0x60 - 0x7F].

Engine Control Commands

AIM_OFF
Description: Turn off aiming pattern
Packet Format
Length
Field Descriptions
Field Name
Length
Opcode
Message
Source
Status
Data
Checksum
Host Requirements
This command applies only to decoders which support an aim pattern (see
If the TRIGGER_MODE parameter is set to HOST, the host can use this command instead of a AIM pull.
Decoder Requirements
The decoder turns off the aim pattern, and responds with a CMD_ACK (if ACK/NAK handshaking is enabled).
If the aim pattern is not supported, the decoder responds with NAK_DENIED (if ACK/NAK handshaking is enabled).
for the protocol required to transmit these messages.
Opcode
0x04 0xC4
Format
Length of message (not
including checksum).
0xC4
4 = Host
Bit 0: Retransmit
Bit 1-7: Unused
2's complement sum of
message contents excluding
checksum.
Message Source Status
0x04
Size
1 Byte Length Field
1 Byte Identifies this Opcode type.
1 Byte Identifies where the message is coming
from.
1 Byte Identifies the transmission status.
Unused bits must be set to 0.
None
2 Bytes Checksum of message.
Table 10-10 on page
Data Checksum
Description
10-19).
SSI