Series 905
Page 8
Design Guide
Evaluation board overview
Connections
The following symbols refer to the picture:
Symbol: Description:
V+ / Gnd
Optional power supply connection.
Vsupply
Choose supply voltage from the DSUB connector or
screw terminals (Vext).
Activity LED Indicates current system status.
Zero Switch
Used to zero the pressure readout at vacuum
Reset
Short circuit and release to reset the microcontroller
on the electronics module.
S.Pin1 / 2 / 3 Can be used to connect the MicroPirani™ sensor to the
socket pins of the electronics module. Each sensor
connection has an associated ground connection.
A+
Differential output.
A -
Differential analog- output.
R1 / R2 / R3 Set point outputs.
RxD
Data receive pin when configured to external
communication.
TxD
Data transmit pin when configured to external
communication.
485
RS485 enable pin.
DSUB
9 pin DSUB communications port.
RxD int / ext Chooses between the ‘RxD’ screw terminal (TTL directly
from the module) or DSUB connector (RS232 or RS485)
as receiver.
TxD int / ext Chooses between the ‘TxD’ screw terminal (TTL directly
from the module) or DSUB connector (RS232 or RS485)
as transmitter.
232 / 485
Chooses between RS232 and RS485 communication.
All three jumpers must be in either the 1-2 or 2-3
position.
Electronics
Mount the electronics module here, notch facing board
module
edge as shown.
D-SUB male connector pinout
1.
<Not used>
2.
<Not used>
3. Power
4. Power supply ground
5. Analog
6.
<Not used>
7. RS232 transmit or RS485-
8. Analog output -
9. RS232 receive or RS485+
Specifications
Supply voltage
9-30VDC via DSUB connector or screw terminals
Dimensions
Approx. 48 x 87mm (1.89 x 3.43 in)
Communication
RS232 / RS485 (9 pin DSUB) or TTL level (via screw terminals)
Sensor connection
Screw terminals or connector on the electronics module
Set point outputs
3 with onboard shunt diodes for use with relays.
Zero switch
Onboard
Figure 6 – The evaluation board
Figure 7 - 9 pin D-SUB interface (at the
connector)
