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VDM300 Vapor Delivery Module
®
3-2-2 Ready-to-Use (Normal Mode)
3-2-3 Zeroing the VDM300
tank and then put back into normal mode as soon as possible (typically less
than 30 minutes)
• lf the VDM300 is put into ldle mode temporarily (typically less than
30 minutes) and then put back into Normal mode
• lf power to the VDM300 is lost or removed temporarily (typically
less than 30 minutes) and the Normal mode signal is present when
power is returned
6. The VDM300 outputs the Ready-to-Use signal(s). Once the VDM300
has completed the Start-up sub-mode, it will pull Pin 13 of the DB-15 to
ground and turn the green "DEVICE READY" LED on. This indicates
that it is in Normal Mode and ready to deliver water vapor on demand.
When the VDM300 is in Normal Mode and has reached its Ready-to-Use
condition, Pin 13 of the DB-15 is pulled to ground and the green "DEVICE
READY" LED is on. The amber "WARM UP" LED will be flashing indicating
that the internal temperatures (MFC and tank) are at set point and stable.
The red "DEVICE FAULT" LED should be off. lf the "DEVICE FAULT" LED is
on, then proceed to Section 4 Maintenance & Troubleshooting.
At this time the VDM300 is ready to receive set points from the tool and
begin delivering water vapor. The set point signal is received from the tool
on Pin 8 of the DB-15. lt needs to be a 0-5 Vdc analog signal. The signal is
interpreted as a scale to represent the full scale flow range of the VDM300.
As an example, a 3 slpm (3000 sccm) VDM300 would interpret a 2.5 Vdc set
point from the tool as a command to flow 50% of full scale which would be
1.5 slpm (1500 sccm). When the VDM300 begins flowing water vapor at the
given set point it will put out a flow signal from Pin 2 of the DB-15. This signal
is an analog 0-5 Vdc signal scaled to represent the full scale flow range of
the VDM300. As an example, a 3 slpm (3000 sccm) VDM300 would output a
2.5 Vdc signal if it were flowing at 50% of its full scale range, which would be
1.5 slpm (1500 sccm). The VDM300 will flow water vapor at 100% of its full
scale range up to a maximum pressure of 200 Torr (26.66 kPa) at its outlet.
It is important to make certain that the Dl water supply is connected to the in-
let and pressurized to 10-40 psig while the VDM300 is in Normal mode. This
is required because the VDM300 will actively maintain a nominal Dl water
level in its tank by periodically refilling itself.
Over a period of time the flow sensor in the VDM300 could accumulate a
zero offset. lt is recommended that the VDM300 flow sensor is zeroed if this
occurs to ensure accuracy when delivering water vapor. There are two ways
to zero the VDM300:
1. Using the "ZERO" momentary switch on the front cover
2. Using the BEST GUI
The following sections explain the manual zeroíng procedure and how the
Auto-Zero feature functions.
Installation and Operation Manual
X-VAP-VDM300-eng
Part Number: 541B210AAG
October, 2018
3-3
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