Siemens SIMATIC CP 440 Manual page 23

Character Delay Time
The figure below shows the maximum time permitted between two characters
received within a message frame. This is known as the character delay time.
Signal
1
Figure 2-2
Point-to-point connection CP 440 Installation and Parameter Assignment
A5E00057742-02
nth character
Character Delay Time
Basic Principles of Serial Data Transmission
(n + 1)th character
Character delay time
Time t
2-5