Measurement Computing USB-3101 - Manual (Page 17)

USB-3101 User's Guide Functional Details
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Caution! The +5V terminal is an output. Do not connect to an external power supply or you may damage
the USB-3101 and possibly the computer.
Synchronizing multiple units
You can connect the SYNCLD terminal pin (pin 49) of two USB-3101 units together in a master/slave
configuration and simultaneously update the DAC outputs of both devices. Do the following.
1. Connect the SYNCLD pin of the master USB-3101 to the SYNCLD pin of the slave USB-3101.
2. Configure the SYNCLD pin on the slave device for input to receive the D/A LOAD signal from the master
device. Use InstaCal to set the direction of the SYNCLD pin.
3. Configure the SYNCLD pin on the master device for output to generate an output pulse on the SYNCLD
pin.
Set the Universal Library SIMULTANEOUS option for each device. Refer to the Universal Library User's Guide
for information on how to configure the USB-3101 with the Universal Library.
When the SYNCLD pin on the slave device receives the signal, the analog output channels on each device are
updated simultaneously.
An example of a master/slave configuration is shown here.
S
Slave
PMD-1608F
Master
device
Slave
device SYNCLD pin
(terminal pin 49)
D/A LOAD signal
Configure the SYNCLD
pin for output
Configure the SYNCLD
pin for input
Figure 8. Synchronizing the update of multiple devices