PM9903BPE

2/22

http://www.sames.co.za

JUMPER SETTINGS

Power supply jumpers

The power supply jumpers are used to disconnect the on-

board power supply, allowing the metering section of the circuit

to be powered from an external power supply if required.

Figure 2: Jumper positions

Shunt/ CT selection Jumper

The PCB makes provision for the use ofa current transformer

in place of the shunt. If required the shunt can be removed and

a current transformer inserted. In this case J7 must be closed

and the applicable CT termination resistor (R26) inserted.

Jumper

Shunt

OPEN

R26 not required

J7

CT

Closed

R26 inserted

Communication jumpers

Jumpers J8 to J11 connect pull up resistors to the SPI inputs

of the SA9903B. The pull up resistors are required by the open

drain outputs of the HCPL2631 opto-couplers. Ifa PC is used

with the PM9903BPE module the jumpers must be closed,

and can be left closed in the case of the SAMES micro-

controller board. This board is capable of driving the SPI bus in

this state. Default Closed.

Jumper

Description

J12

PB (left connection)- Connects the push button

output througha opto-coupler to pin 13 of the

parallel port

FMO (right connection)- Connects pin 15 of the

SA9903B througha opto-coupler to pin 13 of the

parallel port

Parallel Port power supply jumper

Jumper JP4 is used to select the power source for the opto-

coupler U7. Power can be taken from the PC’s parallel port or

from an external5 volt supply via SK3.

Jumper

Description

JP4

Left connection- Power for U7 is taken from the

PC’s parallel port(pins 1, 14,16,17)

Right connection- Connects U7 to SK3. An

external power supply can be connected to

SK3 to power U7.

Jumper

Description

J4

J5

J6

Connects V

to the metering circuitry.

Default closed

DD

Connects V

to the metering circuitry.

Default closed

SS

GND connection point.

An additional output from the module is made available to the

parallel port of the PC. The output can be selected to be the

SA9903B’s FMO output or it can be selected to be the modules

push button output.

sames

PM9903BPE

JP4

J12

J8

J9

J10

J11

JP1

J5

J4

Push button

SK2

PB

FMO*

VSS

VDD

Micro-controller board

AGND

J6

J7

SK1

L

N

SPI

* On some pcb's this may be labled as PB/F150, however FMO and F150 is the same connection.