CAVRO XP 3000 - Page 53

Software Communication 3-17
Example 2. The pump is set to address 6
Pump sends:
Dir Group Device Frame RTR Length
1 001 0110 010 0 0000
Host acknowledges:
Dir Group Device Frame RTR Length Node ID Slave ID
0 001 0000 000 0 0010 0010 0110 0010 0110
Host acknowledges the boot request with:
Dir = 0 Host to slave
Group = 1 Boot request response group
Device = 0 Always 0 in boot response
Note:
Boot MID is the same for all nodes
Frame = 0 Boot request response frame
Rtr = 0 Always 0
Length = 2 Two data bytes in return message
Node ID Group ID (2) + Pump
Address (6)
“&” Hex 26
Slave ID Same as Node ID
(hex 26)
Hex 26
The pump will save the Node ID to use for message filter Group ID.
CAN HOST AND PUMP EXCHANGES
When a slave pump receives a command, finishes a command, encounters an error
condition, or responds to a query, it sends an answer frame to the host using the same
frame type as the command it belongs to. The answer frame format is device dependent.
Generally, it will have the following format:
<MID><DLC><Answer>
Where:
<MID>: 11-bit message identifier. The direction bit is 1. The group number and
the frame type are the same as received. Device is the current device
address.
<DLC>: 4-bit data length code.
<Answer>: Data bytes block. The first byte of the data block is always the status
byte. It is defined as in Table 3-. The second byte is a null character.
The remaining bytes contain the response in ASCII format. If the reply
consists of more than six bytes, the multi-frame messages are used.