ring DNA100, Руководство пользователя, Страница: 24 / 27

June 2017 Digital Network Adapter DNA100
A = Error counter. Maintains total number of errors on network. This number is stored in the network master and
can be reset by resetting the network master. A secure network will have no errors but some are possible if
nodes are installed or disconnected and cause data disturbance.
Possible errors are:
- checksum error
- network error
- receiver overrun error
- noise error
- framing error
- number of retransmits
B = To node. In this example FF indicates a broadcast to all nodes. Other numbers indicate a node address.
C = From node. The example shows node 0C sending to FF (broadcast).
D = Event definition CALL, CONNECT, CLEAR, PARK, TALK, BUSY, etc.
E = Total number of bytes in this packet, 09.
F = Device to/from. The node may represent a device such as a master station. The example shows device 01
(line equipment 01 is the second subscriber port in the CB901) sending to FF (broadcast)
G = Checksum. The total of all data in the packet. This is recalculated when received and checked for accuracy.
If the calculated checksum does not match the received checksum then a request to retransmit the packet
occurs.
H = Time. Time is transmitted by the network master as a broadcast and the time may also be part of a packet
indicating when an event occurred. The format is SS:MM:HH (45:40:19).
I = Date. Date is transmitted by the network master as a broadcast and the date may also be part of a packet
indicating when an event occurred. The format is DD:MM:YY (08:01:03).
J = ASCII text field. The 30 character description for this device.
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Ring-Master