Measurement Specialties PMD-1024HLS - Manual (Page 17)

PMD-1024HLS User's Guide Functional Details
If you want to sink the maximum of 64 mA per DIO line, you can only do so with up to six lines (440 mA
÷ 64 mA/line = 6.8 ≈ 6 lines). To sink current with all 24 DIO outputs at any one time, you can sink a
maximum of 18 mA per line.
Ground terminals
The nine ground ( GND ) connections are identical, and provide a common ground for all PMD-1024HLS
functions. Refer to the pinout diagram on page 3-2 for the location of the GND terminal.
Counter terminal
Pin 20 (CTR) is the input to the 32-bit external event counter. Refer to the pinout diagram on page 3-2
for the location of this terminal. The internal counter increments when the TTL levels transition from low
to high. The counter can count frequencies of up to 1 MHz.
Pull-up/pull-down terminals
You can wire pin 11 (Port C Pull-up/Pull-down), pin 13 (Port B Pull-up/Pull-down), and pin 15 (Port
A Pull-up/Pull-down) to support a pull-up or pull-down connection. These terminals configure the
internal 47K resistors on the PMD-1024HLS.
Refer to the pinout diagram on page 3-2 for the location of these terminals. These terminals are
configured as open by default.
ƒ To configure a pull-up connection for a specific port, wire the pull-up/pull-down terminal to a
USB +5 V terminal.
Figure 3-5. Pull-up connection for Port A
3-5