Krell Industries RS-232 - Manual (Page 6)

RS-232 Status Feedback Description
for the SACD Standard
RS-232 Status Block Descriptions
for the SACD Standard
The SACD Standard reports its operational status by transmitting a block
of status data via the RS-232 connector. The block is configured as three
8-bit words. The first and last word always contains hexadecimal code 55
to facilitate message framing and synchronization. When the data block
is sent through an RS-232 port, each 8-bit word transmitted will also have
1 stop bit associated with it. The exact RS-232 protocol settings for both
status and SACD Standard control are as follows:
9600 Baud 8 Data Bits 1 Stop Bit No Parity
The feedback system is available only through the RS-232 connector.
The status can be activated in two ways. The first is to ask for status to
be sent by sending the RS-232 command code "STAZ". The second is
to enable auto status by sending the RS-232 command code "ASTEZ".
SACD Standard will transmit a status block whenever the status changes.
Auto status is disabled by sending the RS-232 command code "ASTDZ".
Auto status remains enabled until AC power is removed or turned off.
When AC power is reapplied, auto status is disabled.
Word 1: Start of Message
Bit
Description
Bit 7 – 0: Hexadecimal 55
Word 2: General Status I
Bit
Description
Bit 7: Reserved
Bit 6: Reserved
Bit 5: Reserved
Bit 4: Reserved
Bit 3: Reserved
Bit 2: Reserved
Bit 1: Reserved
Bit 0: Power 1=Main power is on
All numeric values described in the following charts are decimal values
unless otherwise noted. The description of the three 8-bit words follow.
The values marked Reserved must be ignored during pattern matching.
7 6 5 4 3 2 1 0
0 1 0 1 0 1 0 1
6 Krell SACD Standard Developer’s Reference
7 6 5 4 3 2 1 0
Reserved Reserved Reserved Reserved Reserved Reserved Reserved Power