Rockwell Automation 1794-IP4 Series B FLEX I/O PULSE COUNTER User Manual - Manual (Page 48)

5–3 How Communication Takes Place and I/O Image Table Mapping with the DeviceNet Adapter
Publication 1794ĆUM016B-EN-P - August 2002
System throughput, from Pulse Counter to backplane, is a function
of:
•
the configured minimum frequency sample time
•
the number of channels actually configured for connection to a
specific sensor (0 or 1)
You can set the minimum frequency time during module
configuration. The selection influences the sample data rate, thus
affecting system throughput.
The number of channels included in each input scan also affects
system throughput.
FLEX I/O Pulse Counter module data table mapping is shown
below.
Pulse Counter Module (1794ĆIP4) Image Table Mapping
Module Image
I/O Image
Input Size
Output Size
0 to 3 Words
1 to 10 Words
Counter 00 - 16-bit period measurement or low word of 32Ćbit period measurement for channel 0
Code for identification of software version
Control Word 0 - Sets the measure function
Control Word 2 - sets the start of a new measurement
Control Word 1 - Sets the clock frequency and period multiple
Counter 01 - pulse counter for channel 0 or high word of 32Ćbit period measurement
Counter 10 - 16-bit period measurement or low word of 32Ćbit period measurement for channel 1
Counter 11 - pulse counter for channel 1 or high word of 32Ćbit period measurement
Counter 20 - 16-bit period measurement or low word of 32Ćbit period measurement for channel 2
Counter 21 - pulse counter for channel 2 or high word of 32Ćbit period measurement
Counter 30 - 16-bit period measurement or low word of 32Ćbit period measurement for channel 3
Counter 31 - pulse counter for channel 3 or high word of 32Ćbit period measurement
Readback of Control word 2 or
Reserved M0 M1 M2 M3
Reserved
Reserved
RD0 RD1 RD2 RD3
System Throughput
Mapping Data into the
Image Table