3 - 12
Cavro® XLP 6000 Modular Syringe Pump Operating Manual, 734237-C, en
3 - Software Communication
Communication Protocols
Device
This is the address of the module in the particular group. Each group can have
up to 16 devices. The address value is 0 - 15.
Frame
This lets the device know what type of message is coming. See “CAN Frame
Types” in this chapter.
RTR
This bit is not used in Tecan Systems’ CAN implementation and should always
be set to 0.
IDE
This will always be set to 0 for standard format frames.
r0
Reserved bit, set to 0.
Length
This is the length of the data block in the message. Data blocks can be from
zero to eight bytes in length.
CAN Frame Types
The frame types allow each device to know what type of command is coming in
and enables faster processing of commands. Pumps respond to the frame types
described below.
“On-the-Fly” Commands (V and T), Type 0
Normal commands use a frame type 1 (i.e., “Action Commands”). Since
commands sent over the CAN bus with a particular frame type must complete
before a subsequent command using the same frame type can be issued, a
different ID must be used when issuing an “on-the-fly” command. For this
reason, “on-the-fly” commands must be issued over the CAN bus with a frame
type of 0 (zero).
When issuing “on-the-fly” commands, the frame type 0 commands will not
generate completion messages and thus no pairing code is needed (these
commands are simply acknowledged immediately).
Action Frames, Type 1
This frame type is used for action commands, such as Initialization
commands, Movement commands, Valve commands, or to set pump
operating parameters. All “task-type” commands are sent in this type
message frame. When multi-frame messages are used to send an action
command, this frame is the end message sent to the pump.