3. OPERATION
Page 45
© 2009 DH Instruments, a Fluke Company
Before operating PPCH with external Q-RPTs, check carefully that the Q-RPT TEST(+) port is
connected to the PPCH TEST port. If the external Q-RPT is NOT connected to the PPCH TEST port, it
will not measure the pressure generated by PPCH and PPCH may reach a pressure higher than the
target pressure before its watchdog function recognizes that the external RPT is not connected.
Take care not to overpressure external Q-RPTs when using them with a PPCH. When using
external Q-RPTs in RPM4s as reference pressure measurement devices with a PPCH, the user is
responsible to setting up hardware and following procedures to protect lower range Q-RPTs from
overpressure. Only the Lo Q-RPT (IL) built-into the PPCH is protected automatically.
OPERATION
To run the Q-RPT and utility sensor search and initialize function, press
[RPT]
. PPCH
displays
<Searching for RPTs…>
while it runs the search function. When the RPT search is
complete, the Q-RPTs identification screen is displayed.
1. IH, and L: Identification of RPTs in Internal (PPCH), Hi and Lo
positions.
2.
X1H and L: Identification of RPTs in External 1 (first RPM4), Hi and Lo
positions.
3.
X2H and L: Identification of RPTs in External 2 (second RPM4), Hi
and Lo positions.
IH:A200Mu L:none
X1H:A200M L:A70M
X2H:A40M L:none
The cursor is on the position designator of the active Q-RPT or utility sensor. Use the cursor
control keys to move the cursor to other positions and to view the third line if present. Press
[ENT]
to make the selected Q-RPT or utility sensor active in its default range (see Section
3.2.6). Press
[RPT]
again to cause the Q-RPT search to run again. Press
[ESC]
to return to the
MAIN RUN screen without making any changes.
See
Table 1 for a listing of Q-RPT designators and their corresponding default ranges and
Table 6 for information on Q-RPT system position identification designators.
For PPCH to successfully identify and initialize external RPM4s, the RPM4 COM1 port
settings must be:
Baud rate: between 1200 and 19200
Parity: Even
Date bits: 7
Stop bits: 1
If PPCH is not able to establish communications with RPM4s and their Q-RPTs, check that the
RPM4 COM1 port setting conform to the requirements above. If the COM1 port settings are
correct, check that the correct communications cable is being used (standard pin-to-pin DB-9M
to DB-9F RS232) and is connected to the correct communications ports.
PPCH COM2 > 1
st
RPM4 COM1; 1
st
RPM4 COM2 > 2
nd
RPM4 COM1
See the RPM4 Operation and Maintenance Manual for additional information on RPM4 RS232
communications and COM port settings.
