# Calculate the Input Delay on NI-9237

Updated Dec 8, 2022

## Reported In

### Hardware

• NI-9237
• NI-9235
• NI-9236
• C Series Strain/Bridge Input Device

## Issue Details

How do I calculate the input delay on the NI-9237?

## Solution

The input delay of C Series Strain/Bridge Input Module, such as NI 9235/9236/9237, can be calculated from the Data Rate (fs).

The Data Rate is the rate at which you collect data. When you see the specification of NI 9237, you can find the below equation.

Data Rate (fs) = (fM÷256)÷n, where n is any integer from 1 to 31.

And then, This Data Rate is used in the below equation.

Input delay = (40 + 5/512)÷ƒs + 4.5 µs.

For Example,

Master Timebase (fM): 12.8 Mhz (Internal)
Integer: 25

• Data Rate (fs) = (fM÷256)/25
Data Rate (fs) = 2 kS/s

• Input delay = (40 + 5/512)÷ƒs + 4.5 µs.
Input delay = 0.0200094 s

Note: When programming, you do not specify the integer value for division on the NI 9237, and you will actually specify your Data Rate.  If your Data Rate does not match a Data Rate that is calculated using an integer, it will be coerced up to the next highest Data Rate.