Siemens SINAMICS S120 Installation And Start-Up Manual page 142

Communication via PROFIBUS
Motion control with PROFIBUS
Table 4-18 Time settings and meanings, continued
1)
Name Value
T 1
MAPC
T
SAPC
T 5DC hex
BASE_IO
8
1500 dec
T 2
I
T 4
O
T E10 hex
DX
8
3600 dec
4-142
Limit value
T = 8 Minimum DP cycle time
DP_MIN
Calculation: T
n S T
Master application cycle time
DP
n = 1 – 14 This is the time frame in which the master application
generates new setpoints (e.g. in the position controller
cycle).
Calculation: T
Slave application cycle time
– Time base for T
Calculation: T
T
Bit
v T
T < T Time of actual-value sensing
I_MIN I DP
This is the time at which the actual position value is cap-
tured before the start of each cycle.
T = integer multiple of T
I
Calculation: T
For T
T = 1 Minimum T
I_MIN
Calculation: T
T + T Time of setpoint transfer
DX O_MIN
v T v T
O DP This is the time at which the transferred setpoints (speed
setpoint) are accepted by the closed-loop control system
after the start of the cycle.
T = integer multiple of T
O
Calculation: T
For T
T = 1 Minimum time interval between T
O_MIN
T
O_MIN
T < T Data exchange time
DX DP
This is the time required within one cycle for transferring
process data to all available slaves.
T
DX
T
Bit
Calculation: T
SINAMICS S120 Installation and Start-Up Manual, 12/04 Edition
Description
= 8 S T
DP_MIN BASE_DP
= 1 S T
= 1 ms
MAPC DP
, T
I O
= 1500 S T
BASE_IO
= 1/12 µs at 12 Mbaud
BASE_IO
= 2 S 125 µs = 250 µs
I
= 0: T = T
I I DP
I
= 1 S T
I_MIN BASE_IO
BASE_IO
= 4 S 125 µs = 500 µs
O
8 T
= 0: T
O O DP
= 125 µs
= 1 S T
BASE_IO
= integer multiple of T
Bit
= 1/12 µs at 12 Mbaud
= 3600 S T
DX BIT
E Siemens AG, 2004. All rights reserved
= 1 ms
= 125 µs
Bit
= 125 µs
and T
O DX
= 300 µs