Siemens PID Manuals

Modular PID Control
http://rapidshare.com/files/46061531/Pid_e.pdf.html

Standard Software
for S7-300 and S7-400 PID Control
http://rapidshare.com/files/46059104/S7pidcob.pdf.html

PID Control: http://rapidshare.com/files/46059105/S7tmpcob.pdf.html