Teledyne D series Installation And Operation Manual page 171

All the parameters are as previously described except message
destination. Message destination is the 1-digit identification
number of the unit that the message is sent to.
An example of a typical data exchange is summarized below. For
illustration, we will assume the network consists of a computer
serving as a combination network controller and master. There
will be one slave unit; a Model 260D pump. Details on the pump
message format are in section 8.8. The computer will be unit #0,
and the pump will be unit #6.
Network Controller and Master Unit #0
[CR]1R 5D[CR]
Note
A [CR] must start the network. The controller is checking for
the presence of unit #1 but will get no response in 200 ms
because there is no unit 1.
Network Controller and Master Unit #0
1R 5D[CR]
Still no response.
Network Controller and Master Unit #0
1R 5D[CR]
Still no response, so unit 1 will be dropped from the poll.
Network Controller and Master Unit #0
2R 5C[CR]
Checks for unit 2 but will get no response in 200 ms
because there is no unit 2.
Network Controller and Master Unit #0
2R 5C[CR]
Still no response.
Network Controller and Master Unit #0
2R 5C[CR]
Still no response, so unit 2 will be dropped from the poll.
In this way units 3-5 will be checked and dropped from the poll.
Network Controller and Master Unit #0
6R 58[CR]
Check for presence of unit 6.
Unit 6
R 8E[CR]
Unit 6 responds.
Network Controller and Master Unit #0
7R 57[CR]
Since unit 7 does not exist, it will be dropped from the
polling scheme.
Network Controller and Master Unit #0
6R008IDENTIFY84[CR]
The master verifies the fact that unit 6 is a Model ___D. In
D Series Syringe Pumps
Section 8 Serial Interface
8-17