Bronkhorst EtherCAT - Manual (Page 13)

BRONKHORST ®
4.1.1.2 Generated Object Dictionary
All available parameters in Bronkhorst instruments are described in 9.17.023. These parameters are accessed by
means of a process / process parameter number combination. For a selection of these parameters objects are
generated and added to the Object Dictionary at instrument startup (in the range 0x2000 – 0x3000). The mapping
from process / process parameter number combination to objects is done in the following way:
object index = 0x2000 + process number
subindex = process parameter number + 1
subindex channel 1 = process parameter number + 1
subindex channel 2 = process parameter number + 1 + 100
subindex channel 3 = process parameter number + 1 + 200
etc.
The sub-indexes for channel 2 and up are only applicable for multi-channel systems.
Example:
DDE parameter 8: Measure has process / process parameter number combination 1 / 0. So this parameter is mapped
to object index 0x2001 (= 0x2000 + 1) and subindex 1 (= 0 + 1).
For the following DDE parameters (among others) objects are generated:
8 Measure
9 Setpoint
10 Setpoint slope
21 Capacity
24 Fluid number
92 Serial number
205 fMeasure
206 fSetpoint
4.2 P
ROCESS
D
ATA
(PDO)
The Process Data are organized in process data objects (PDO), which are transferred using the efficient means of
EtherCAT.
Objects from the Object Dictionary, which can be mapped to the PDO, can be added to the PDO Map before activating
the configuration. It is possible to add 20 objects to the RxPDO Map (0x1700) and 20 objects to the TxPDO Map
(0x1B00).
Which objects from the the Object Dictionary can be mapped to the PDO, can be found in Appendix A: Object
Dictionary.
All objects in the range 0x2000 – 0x3000 can be mapped to the PDO, except the ones containing strings.
Page 13 EtherCAT interface 9.17.063