Rockwell Automation 1753-DNSI DeviceNet Safety Scanner for GuardPLC Controllers - Manual (Page 118)

Publication 1753-UM002A-EN-P - July 2005
D-2 Calculate Safety Connection Bandwidth
Single-cast Outputs 1 to 2 Bytes
In the equation below:
A = 1
÷ Data_RPI ÷ 0.001
B = Safety_Data_Size + 6
C = (B x 8 x bit_stuffing_factor) rounded to the nearest whole number
D = 1
÷ (Data_RPI x 19) ÷ 0.001
%Bandwidth = 100 x {[A x (57 + B x 8 + C) + (D x 115)]
÷ Baud_Rate}
3 to 250 Bytes
In the equation below:
A = 1
÷ Data_RPI ÷ 0.001
B = (2 x Safety_Data_Size) + 8
C = (B
÷ 8) rounded to the nearest whole number
D = 1
÷ (Data_RPI x 19) ÷ 0.001
E = (B x 8 x bit_stuffing_factor) rounded to the nearest whole number
%Bandwidth =
100 x
( {A x [(57 x C) + (B x 8) + E] + (D x 115)}
÷ Baud_Rate )
Multicast Connections 1 to 2 Bytes
In the equation below:
A = 1
÷ Data_RPI ÷ 0.001
B = Safety_Data_Size + 6
C = (B x 8 x bit_stuffing_factor) rounded to the nearest whole number
D = 1
÷ (Data_RPI x 100) ÷ 0.001
%Bandwidth =
100 x {[A x (57 + B x 8 + C) + 2 x (D x 115 x Number_of_Consumers)]
÷ Baud_Rate}