Slerj SSR-1U, User Manual, Page: 22 / 66

SSR-1U User’s Manual
Rev -, 27 Dec 2019
© 2019 Slerj, LLC
22
www.slerj.com
For example, a Count of 0x80 would indicate a payload of 128 bytes. A Count of 0x81 would
indicate a payload length of 136 bytes. The longest payload supported by this implementation is
(Count = 0xFF) 1144 bytes. When the MSb of Count is set, the payload length will be modulo 8.
In the control protocol, all multi-byte values are sent most significant byte first (i.e., big endian).
In this document, messages are divided into two groups: general messages and messages used to
set and query configuration. In the message definitions, types will be identified by the following
abbreviations shown in Table 11.
Table 11. Control Protocol Type Definitions
Type Description
U1 Unsigned 8 bit integer
U2 Unsigned 16 bit integer
U4 Unsigned 32 bit integer
I1 Signed 8 bit integer
I2 Signed 16 bit integer
I4 Signed 32 bit integer
B x String of x bytes
BN Variable length string of bytes
5.2 General Messages
General messages (Table 12) provide access to command functions and status of the SSR-1U.
All general messages received by the SSR-1U will be answered with a message to acknowledge
(ACK), to negatively acknowledge (NACK), or to provide the requested data.
Table 12. General Control Protocol Messages
ID Direction
1
Description
0x10 in Record
0x11 in Stop
0x20 out Command Status
0x21 out Card Status
0x22 out Disk Status
0x24 out All Channel Status
0x30 in Set Date
0x30 out Date
0x31 in Set Time
0x31 out Time
0x50 in Configuration Set
0x51 out Configuration Query
0x99 in Reset
1
Direction is from the SSR-1U’s point of view