CT2565 Aeroflex Circuit Technology, CT2565 Datasheet - Page 7

• Manufacturer Part Number: CT2565
• Description: CT2565 Bus Controller/ Remote Terminal and BUS Monitor FOR MIL-STD-1553B
• Manufacturer: Aeroflex Circuit Technology

Aeroflex Circuit Technology
RTU Response
The addressed RTU(s) must respond (to
non-broadcast commands) within a timeout
period as shown in Figures 7, 8, and 9. Figures
10 and 11 illustrate the BC Mode Code Timing.
Status and data words received from the 1553
port are transferred to the subsystem via a
handshake and memory write operation for each
(See Message Length Checking).
BC Status/Error Handling
Message transfer errors are indicated using the
TIMEOUT, MSGERR, LOOPERR and STATERR
BC status outputs (pins 4, 30, 46 and 68
respectively).
methods include user evaluation of status, data
and (long) loop words and/or use of the 1553B
dual redundant mode codes. Note that certain
error conditions not reflected in the current
Status Word (SW) can occur; Broadcast CMD
RT-status and post RT status response may be
Notes:
(1) LOOPERR is a .5µS pulse which occurs near DMA handshake for loop back word.
(2) TIMEOUT is a 40/160nS pulse which occurs 19.5µS ±0.5µS after the mid-bit parity of the last word onto the bus.
(3) STATERR is a 120/166nS pulse which occurs during the status word DMA handshake.
(4) MSGRR is a 40/160nS pulse which occurs approximately 100nS before INCMD goes high. It is triggered by NODT going inactive (i.e.,
CONTROL/COMMAND WORD 1
LOOPED WORD
RT-RT
STATUS WORD
DATA WORD
FORMAT ERROR
TRANSFER/CONDITION
Handshake Failure
Data Received from RTU
Data after Status Set
low word count).
Handshake Failure
Short Loop Failure
Long Loop Failure
No Status Received within 15.5µS
RT Address Mismatch
Error Flag(s) Set
Broadcast Received bit Set
Transmit Command
Receive Command
Less than word count
Greater than word count
(all extra words)
Additional
error
Memory read by BC subsystem.
Looped back through receiver.
Status-RT1, data, status-RT2 response
NODT timeout
Command RTU Address
Status Word Response from RT:
Response to Transmit Status Word mode
No subsystem response to Bus Request.
Transmit Command (RTU response)
More data received than requested.
Transmit Command: data words received
DESCRIPTION
command may allow this, all others ERROR.
Table 4 – BC Error Handling
Data lost: Word Count fails.
1553 transmission gap.
after status to subsystem.
No response to Bus Request within timeout
period.
Received Word
DMA/Write looped word to subsystem.
to follow receive, transmit, commands.
RTU Address
Error Condition
detection
last xmitted word.
7
-
accessed via the Transmit Status Word mode
command.
Transmit Bit Word. Additional status informa
tion is generated by an RTU (CT2565 for each
transfer in the form of a BIT word). This word
may be accessed by the BC using the
TRANSMIT B-I-T WORD mode command. See
RTU Error Handling and Mode Code sections).
Message Length Checking. The BC stores the
command word, word-count field in an internal
register. By decrementing this register following
each data word transfer (See BC Memory
Read/Write Timing), the BC can detect an
incorrect message length.
For a description of the possible BC error,
indicators occurring during each stage of
message transfer read from left to right in
Table 4. For a description of the possible causes
of errors within a transfer, read from right to left.
Status Word
(See definitions in
TIMEOUT
EOM
STATERR
STATERR
Broadcast Mask not set
(See BC Control Word)
STATERR
BC waits for Grant.
MSGERR
Status Word response:
STATERR
MSGERR and EOM
MSGERR and EOM
DMA/memory write
(for each)
MSGERR
STATUS/DATA WORD
below)
SCDCT2565 REV B 8/10/99 Plainview NY [phone]
BC waits for Grant
(no 1553 timing error)
LOOPERR
User Defined
ERROR SIGNAL
PIN
-
46
-
-
4
57
68
68
68
30
68
4
30
30
-