Grass Valley Performer SD - Manual (Page 163)

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Serial Protocol Descriptions
TEN–XL SMPTE Protocol
This protocol is compatible with the SMPTE protocol used by the
TEN–XL Routing Switcher. It is essentially the SMPTE RP113
Machine Control protocol (with minor violations) and makes use
of non-standard messages. The protocol uses SMPTE standards
ESCAPE feature to escape to non-standard message processing.
When queried for status by the bus controller, it always responds
with the same message: the current router status. If you are
currently using this protocol to control a TEN–XL and wish to add
or substitute a Performer, this allows you to do so with no
programming changes. A port speed of 38.4K baud is
recommended, even parity.
The state diagram below illustrates the processing of this protocol.
On comparing this with standard SMPTE, note the listed
differences.
ACTIVE
SELECT
IDLE POLL POWER ON
RESET
R (SEL ADDR)
R (BREAK)
(FROM ANYWHERE)
R (BREAK)
R (POLL ADDR)
R (UNDEFINED)
(FROM ANYWHERE)
≥ 6 CHARACTER
GAP (TIMEOUT)
T (STATUS BYTE)
R (POLL ADDR)
R (TEN) T (STATUS)
IDLE
R (ESC)
R (READ
COMMAND)
R (WRITE
COMMAND)
SET XPTS IDLE
T (ACK)
T (ACK) (IF OK)
R (SEL ADDR)
1. No ACK after receiving ESC.
2. No STX after receiving TEN (before sending response
message).
3. Returns to IDLE after sendingStatus Response message
instead of waiting for ACK or NAK and remaining in the
Select state.
4. Does not support Group Select.
5. Does not support Group Assign.
6. Does not support any standard SMPTE messages
including low-level system messages such as RESET.