CANopen add-on module
SFIDK.PS.023.A2.02
12
6. PDOs (Process Data Objects)
6.
PDOs (Process
Data Objects)
6.1
What is a PDO
Process Data Objects are used to transmit any process data for the process control. The process
data are transmitted without any protocol overhead and by use of the producer/consumer
communication model. All CANopen devices within the network receive the PDO. These devices
are called consumers. Such a consumer can be any kind of output device; this includes devices
with physical outputs like digital outputs or drives, as well as devices with logical outputs such as
control units.
The PDOs are transmitted as broadcasts and therefore without any confirmation back to the
transmitting device. PDOs are controlled in two ways:
•
Its communication behaviour represented by the PDO communication parameters
•
Its content represented by the PDO mapping parameters.
Two types of PDOs are possible; PDO’s received by the device (RX PDOs) and PDOs transmitted
by the device (TX PDOs).
MASS 6000 default TX PDO
PDO
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Byte 7
1
Massflow - float 32
Totalizer 1 - float 32
2
Density - float 32
Temperature i16
Fraction A % i16
3
Volumeflow - float 32
Totalizer 2
(2)
- float 32
4
Fraction A
(1)
-
float 32
Fraction B
(1)
- float 32
(1)
A SENSORPROM
unit with valid fraction data is required.
(2)
If batch is on, batch progress is returned. Otherwise the totalizer 2 values is returned.
MAG 6000 default TX PDO
PDO
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Byte 7
1
Volumeflow - float 32
Totalizer 1 - float 32
2
Totalizer 2
(2)
- float 32
Reserved
(2)
If batch is on, batch progress is returned. Otherwise the totalizer 2 value is returned.
The byte ordering is according to the CANopen specification CiA DS-301.
Units are all SI units, except for temperature, which is in
°
Celsius. Please see appendix A for more
information.
The PDOs can be turned off, and the contents can be changed as needed. If any changes are
made, the settings must be set every time the device is powered up. Please see the SDO chapter
for more information.
MAG 6000/MASS 6000 default RX PDO
6.1.1 TX PDOs
6.1.2 RX PDOs
PDO
Byte 0
Byte 1
1
ControlSet 1
ControlSet 2
Please look at
System Control index 0x2810 in the SDO chapter, for a detailed description.