Specifications

Net-2000™ VCU Users Manual
Version 4.0, December, 2013
Interface Protocol
6.3.5.2 Ack Packet Bytes 2 & 3 (type)
The type parameter (bytes 2 and 3) is 16-bits packet type and is always 0x0000 for ack packets.
type = Packet type
16 bit Word
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Byte 2 Byte 3
Hex Value
Ack 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0x0000
Table 46 type Header Parameter
6.3.5.3 Ack Packet Bytes 4 & 5 (seq)
Bytes 4 and 5 hold the 16-bit sequence number (see Table 47). The sequence number is used as a method to detect
if and when data packets are dropped, so it is important to ensure that consecutive sequence numbers are transmitted
for channel data packets during operation.
seq = Sequence number*
16 bit Word
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Byte 4 Byte 5 Decimal Value
Minimum Value 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -32768
Maximum Value 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 32767
Table 47 seq Header Parameter
*Note: Sequence numbers should be incremented by one every time a packet is
transmitted. When the sequence number reaches 32767, the next valid sequence
number is -32768.
6.3.5.4 Ack Packet Bytes 6 & 7 (cmd)
The cmd element is used to indicate the packet type being acknowledged. Since Reset packets are the only packets
acknowledged this value is always zero.
cmd parameter
16 bit Word
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Packet Type Ack’ed
Byte 6 Byte 7 Hex Value
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0x0000
Table 48 cmd parameter
(Subject to Change) Page 57
DVSI CONFIDENTIAL PROPRIETARY