Leuze electronic DDLS 200 Series - Time Behavior

DeviceNet / CANopen
48 DDLS 200 Leuze electronic
9.7.2 Time behavior
Telegram delay from segment to segment
• Typical propagation time delay of the messages in one direction
• Calculated with 10% stuffing bits
Message memory not sorted (FIFO)
Message memory sorted
The maximum delay depends on various boundary conditions:
• Bus load
• Message priority
•History
• Sorting active / not active
If a slave is addressed by a participant along an entire segment and expects an answer, twice the
propagation time must be planned for (twice the optical path).
If multiple optical paths are used in a system, the delay times may be added (depending on the con-
stellation in the bus).
The increased delay times must be taken into consideration when parameterizing the system.
Number of bits in the telegram • 1.1 • (0.5µs + T
bit
) + 10µs
Number of bits in the telegram • 1.1 • (0.5µs + T
bit
) + 45µs
Example 1: DeviceNet Example 2: CANopen
• 125kBit/s (  T
bit
=8µs)
• 4 bytes of data
• Message memory sorted
• 1MBit/s (  T
bit
=1µs)
• 8 bytes of data
• Message memory not sorted (FIFO)
Protocol overhead 47 bits Protocol overhead 47 bits
Data 32 bits Data 64 bits
Stuffing bits 8 bit Stuffing bits 12 bits
 Number of bits in the telegram 87 bits  Number of bits in the telegram 123
bits
1 • telegram length 696 µs 1 • telegram length 123µs
1 • Number of bits • 0.5µs 44 µs 1 • Number of bits • 0.5µs 62 µs
Processing 45 µs Processing 10µs
Typ. total delay 785 µs Typ. total delay 195µs
DDLS200_E.book Seite 48 Mittwoch, 19. Februar 2020 12:22 12