
RX
CMD
DATA DATA
DATA
*
STATUS
TX
CMD
DATA DATA
DATA
*
STATUS
DBC
CMD
 *
   he device will respond with status.
Error Conditions
STATUS
10
SCDCT2578  REV B   3/11/98
Error Conditions
Action taken by device
Error Conditions
Action taken by device
1. Invalid command.
No response.
Command ignored.
2. Non contiguous
     command words.
No status response.
Set message error.
Sequence terminated.
3. Transmit command
    followed by another word
    (excluding command
    word for RTA, in which
    case it will respond to
    the latest command).
No status response.
Set message error.
Sequence terminated.
4. Transmitting terminal
    does not respond with
    status within 16 uS.
No status response.
Set message error.
Sequence terminated.
5. Incorrect terminal
    transmitting.
No status response.
Set message error.
Sequence terminated.
6. Non contiguous data
    following status from
    RTB.
No status response.
Set message error.
Sequence terminated
     equal to receive word
     count.
Set message error.
Sequence terminated.
7. Invalid data transmitted
    from RTB.
No status response.
Set message error.
Sequence terminated.
8. Too few or too many
    data words.
No status response.
Set message error.
Sequence terminated.
WRAP AROUND
  he wrap around capability is for test purposes only.  It will test for
transfers to and from the Bus Controller without any sub system
intervention.
  he wrap around sequence will commence on receipt of a valid
receive command word containing the wrap around subaddress
(1E) providing the WRAPEN input is set high. The data received
is stored in the data buffer memory and the device will respond
with status. The Bus Controller will then send a transmit command
to subaddress 1E and the data contained in the memory will be
transmitted following the status.
  or the test to operate correctly the number of data words to be
transmitted must be the same as the number received.
1. Invalid receive command.
No response.
Command ignored.
2. Invalid data word.
No status response.
Set message error.
Sequence terminated.
3. Non contiguous data.
No status response.
Set message error.
Sequence terminated.
4. Too few or too many
    data words.
No status response.
Set message error.
Sequence terminated
5. Invalid transmit
     command.
No response.
Command ignored.
6. Transmit command
    followed by another
    word.
No status response.
Set message error.
Sequence terminated
7.Transmit Broadcast
   address.
No status response.
Set message error.
Set broadcast.
Sequence terminated.
8. Transmit word count not
No data transmission.
DYNAMIC BUS CONTROL (00)
Action taken by device
1. Invalid command.
No response.
Command ignored.
2. Command followed by
     another word.
No status response.
Set message error.
Sequence terminated.
3. T/R bit of command set
    to zero.
No status response.
Set message error.
Sequence terminated
4. Broadcast address.
No status response.
Set message error.
Set broadcast.
Sequence terminated.
5. T/R bit of command set
    to zero and broadcast
    address
No status response.
Set message error.
Set broadcast.
Sequence terminated.