System information

Section 2. Protocols and Packet Types
2-2
Link-State Sub-protocol Packet Format:
Name Type Description
LinkState bits7..4 The packet type and the link state:
1000: Off-line
1001: Ring
1010: Ready
1011: Finished
1100: Pause
DstPhyAddr 12 bits Address where this packet is going
ExpMoreCode bits 7..6 Expect more communication with this same
destination-source pair soon described
binaurally:
00: Last
01: Expect more
10: Neutral
11: Reverse
Priority bits 5..4 Priority – Ranges from 0 as the lowest priority
to 3 as the highest priority
SrcPhyAddr 12 bits Address of the node sending this packet
{ HiProtoCode bits 7..4 Designates the higher level protocol
DstPBAddr 12 bits Address where this packet is going
HopCnt bits 7..4 Hop count – measured from the source node
SrcPBAddr 12 bits Address of the node sending this packet
{ MsgData }} Byte [ ] Message data
2.2 PakBus Control Packets (PakCtrl)
The PakBus Control Protocol (PakCtrl) facilitates communication and network
management on the PakBus network by exchanging information between
network nodes. Along with the standard PakBus header and SerSyncByte
framing characters, all PakCtrl protocol message bodies also include a two-
byte header consisting of a message type code used to uniquely identify the
format of the rest of the message and a transaction number used to detect
orphaned transactions. While the message type code must be specific to the
message that follows, the application assigns and monitors the transaction
number for each packet.
The PakCtrl message types that an application must be aware of and
understand include the following:
2.2.1 Delivery Failure Message (MsgType 0x81)
The delivery failure or fault message is generated at any node on the network
when a message cannot be delivered. To avoid an endless loop, fault messages
are not generated when an existing fault message cannot be delivered.