About the block identification?

I was make a model for BLDC motor control using PID controller. As I was designing a gate pulse model for inverter application, I came across with these two blocks. Can anyone tell me which block is this and Why it is used?

Answer 1

[Walter Roberson]

I do not recognize the first of those.

The second of those is an absolute value block, https://www.mathworks.com/help/simulink/slref/abs.html

[Rushi Patel]

Thank you for your help. @Walter Roberson