Festo VTSA Series Description page 106

3. Installation
3−30
Note
Valve terminal with soft−start valve:
If a soft−start valve is used in the VTSA valve terminal, no
additional pressure−supplying components may be used
in the same pressure zone.
Exhaust air cannot be expelled via the soft−start valve. If
a pressure zone is operated with a separate duct (1) and
3/5 duct, an exhaust plate is required in this pressure
zone.
Depending on the positions of the soft−start valve on the
·
valve terminal, the pressure zones and the pilot air sup
ply variants, the ports on the right end plate/pneumatic
supply plate are to be sealed with blanking plugs.
Important information about this can be found in the
VABV−S6−1Q−...assembly instructions.
Festo P.BE−VTSA−44−EN en 0905e