Hello m.mahdavi,

there are different possibilities:

1. You can configure the blocksize in the Alarmlogging Editor.
see manual
"SIMATIC HMI WinCC V7.5 SP1 WinCC Information System"
"How to change properties of a message nlock"

Number of characters
14:36 22.11.202114:36 22.11.2021Number of characters that are available for display of the message block in Runtime

https://support.industry.siemens.com/cs/ww/en/view/109772961/65881494795

2. Or you configure the blocksize in the AlarmControl independing of the
project settings, 14:40 22.11.2021

see manual
"SIMATIC HMI WinCC V7.5 SP1 WinCC Information System"
"How to configure the message blocks"

https://support.industry.siemens.com/cs/ww/en/view/109772961/82232055819

3.Deactivate the "Apply project settings" option to let you add or remove
message blocks for the message lists, or to configure message block properties.
The changed properties are stored in the picture. Changes to properties made
in "Alarm logging" are ignored in this control.

Regards

Georg Berghof