WIKA D-21-9 - Manual (Page 46)

D-20-9 / D-21-9 GB
WIKA Additional Instructions Pressure Transmitter with CANopen Interface D-20-9 / D-21-9 46
By means of the table_selector the bit timing parameter table to be used is specified. In the bit timing
parameter table the bit timing parameters for different baud rates are specified. With table_selector
value ´0´ the standard CiA bit timing parameter table is referenced. The table_index selects the entry
(baud rate) in the selected table (value ‘0’ refers to the highest baud rate).
Baud Rate (kBit) Table Index
1000 0
800 1
500 2
250 3
125 4
100 (reserved) 5
50 6
20 7
10 8
This service has to be followed by an Activate Bit Timing Parameters service to activate the configured
parameters. After execution of the Configure Bit Timing Parameters service the node may not execute
any remote LSS services except the services Configure Bit Timing Parameters, Activate Bit Timing
Parameters and Switch Mode.
The remote result parameter confirms the success or failure of the service.
Activate Bit Timing Parameters
By means of the Activate Bit Timing Parameters service the LSS Master activates the bit timing as
defined by the Configure Bit Timing Parameters service.
The switch_delay parameter specifies the length of two delay periods of equal length, which are
necessary to avoid operating the bus with differing bit timing parameters. Each node performs the
actual switch of the bit timing parameters ´switch_delay´ milliseconds after the reception of the
command. After performing the switch, a node does not transmit any messages before the second
time ´switch_delay´ has passed.
LSS Protocol Descriptions
A protocol description specifies the sequence of COB's and their format that are exchanged between
the LSS Master and LSS Slave(s) for a particular LSS service. Requesting Messages (from LSS
Master) using COB-ID 2021. Response Messages (from LSS Slave) using COB-ID 2020.
LSS uses command specifiers to identify the commands.
SWITCH MODE PROTOCOLS
Switch Mode Global
LSS-Master sends
ID DLC Byte0 Byte1 Byte2 Byte3 Byte4 Byte5 Byte6 Byte7
7E5h 8
CS =
04h
mode reserved
cs: LSS command specifier
04 for Switch Mode Global
mode: The LSS mode to switch to:
0: switches to operation mode
1: switches to configuration mode