Endress+Hauser Cerabar M PMC51 - Page 30

Cerabar M PMC51, PMP51, PMP55
30 Endress+Hauser
Dynamic behavior, PROFIBUS PA
Dead time (t
1
) Dead time (t
1
) +
Time constant T63 (= t
2
)
Dead time (t
1
) +
Time constant T90 (= t
3
)
Min. 85 ms 170 ms 235 ms
Max. 1185 ms 1270 ms 1335 ms
Reading cycle (SPS)
• Acyclic: typically 25/s
• Cyclic: typically 30/s (dependent on the number and type of function blocks used in a closed-
control loop)
Cycle time (update time)
Min. 100 ms
The cycle time in a bus segment in cyclic data communication depends on the number of devices, on
the segment coupler used and on the internal PLC cycle time.
Dynamic behavior, FOUNDATION Fieldbus
Dead time (t
1
) Dead time (t
1
) +
Time constant T63 (= t
2
)
Dead time (t
1
) +
Time constant T90 (= t
3
)
Min. 95 ms 180 ms 245 ms
Max. 1095 ms 1180 ms 1245 ms
Reading cycle
• Acyclic: typically 5/s
• Cyclic: max. 10/s (dependent on the number and type of function blocks used in a closed-control
loop)
Cycle time (update time)
Cyclic: min. 100 ms