S800 I/O Station Data Scanning - ABB S800 Product Manual

S800 I/O Station Data Scanning

Calculation of Bus Cycle Time
How to calculate the Bus Cycle Time, see documentation for current master.
To calculate the Bus Cycle Time the following parameters for the I/O station shall
be used:
Number of input and output bytes.
MAX T
See GSD file.
S800 I/O Station Data Scanning
The ModuleBus data is scanned (read or written) cyclically, depending on the I/O
module configuration. To calculate the I/O scan cycle time in the FCI do as follows:
Totalize (number of module type x) * (used execution time for type x) 
(see
the total value to the nearest higher multiple of 2 to get the I/O scan cycle time.
If CI810A or C1810B is used, the scan cycle time is increased by 25% and for
CI820 it is increased by 50%. If the value is a multiple of 2, add 2 to the value.
Otherwise increase the value to the nearest higher multiple of 2, to get the I/O cycle
time.
AI801, AI810, AI890, AI895
AI820
AI825
AI830, AI830A, AI835, AI835A
AI893
138
Maximum Station Delay of Responder in T
SDR
Table 28) if the value is a multiple of 2, add 2 to the value. Otherwise increase
Table 28. I/O Scan Cycle Time in the FCI
Module Type
Section 3 Technical Data and Performance
BIT
Execution Time Used in ms
CI810,
CI801
CI820
Single I/O
3.00 3.00
1.50 1.50
1.50 -
0.40 0.40
0.40 -
(Bit Time). 
CI840
Redundant
I/O pair
3.00 -
1.50 -
1.50 -
0.40 -
0.40 -
3BSE015969-600 A