12
Model 7706 module
Setting the digital outputs in 16-bit (word)
NOTE
Setting the digital output in 16-bit (word) can be accomplished only over the bus (no front panel operation).
To set the digital outputs in 16-bit, send the decimal equivalent of the binary pattern desired (similar to 8-bit). The binary pattern
will be twice as long as the 8-bit pattern (requiring both digital output ports). Keep in mind that bit 15 is the most significant bit
(MSB) and bit 0 is the least significant bit (LSB). This makes the pin 1 screw terminal of Channel 21 (TE2) the LSB and the
pin 10 screw terminal of Channel 22 (TE1) the MSB.
To find the decimal equivalent of the binary pattern, first determine the pattern mapped to the screw terminals on the desired
digital output (refer to the example contained in
Figure 12
). Setting a bit to a logic ‘1’ effectively sets the screw terminal to +5V
while setting it to a logic ‘0’ sets the screw terminal to 0V. Then, for each screw terminal (or bit position), multiply the binary
value (either a 1 or a 0) by the decimal weight (see
Figure 12
). The sum of the products is the decimal equivalent value of the
binary pattern. This decimal value can be sent over the bus as in the example.
The digital output allows the use of an external power supply up to 42V. Refer to
Figure 13
.
Inductive loads
Model 7706 operation is specified for resistive loads. Reactive (inductive) loads require voltage clamping. Before using induc-
tive loads, take adequate circuit protection measures (refer to the appropriate appendices of the Model 2700 User’s Manual).