7 - 8 DS4308/DS4308P Digital Scanner Product Reference Guide
Encapsulation of RSM Commands/Responses over SSI
The SSI protocol allows the host to send a command that is variable in length up to 255 bytes. Although there
is a provision in the protocol to multi-packet commands from the host, the scan engine does not support this.
The host must fragment packets using the provisions in the RSM protocol.
Command Structure
The expected response in the positive case is SSI_MGMT_COMMAND which may be a multi-packet
response. For devices that do not support the SSI_MGMT_COMMAND, the response is the standard
SSI_NAK.
Response Structure
Byte 7 6 5 4 3 2 1 0
0 Length (not including the checksum)
1 SSI_MGMT_COMMAND (0x80)
2 Message Source (4 - Host)
3 Reserved (0) Reserved (0) Reserved (0) Cont'd packet Retransmit
4 Payload data (see the following example)
...
Length -1
Length 2's complement checksum (MSB)
Length +1 2's complement checksum (LSB)
Byte 7 6 5 4 3 2 1 0
0 Length (not including the checksum)
1 SSI_MGMT_COMMAND (0x80)
2 Message Source (0 - Decoder)
3 Reserved (0) Reserved (0) Reserved (0) Cont'd packet Retransmit
4 Payload data (see the following example)
...
Length -1
Length 2's complement checksum (MSB)
Length +1 2's complement checksum (LSB)
To Next Page
Loading...
Need help?
General
