ADLINK ACL-8454/12 - Manual (Page 27)

Installation & Configurations • 19
2.10 Gate Control Configurations
The gate control signals of the independent counters are internally pulled
high hence they are default enabled if no external gate used. When the
external gate signals are used, the counters can be used to measure pulse
width. Moreover, the gate of counter #1 ~ #4 come from the reverse of
counter #6 output by jumper selecting. Therefore, the time interval of the
counter gate can be precisely controlled and frequency measurement is
possible. Figure 2.14 shows the jumper setting of gate control of counter
#1~ #4.
ExtG n
GATE n
(1) Jumper NOT installed : External gate control
/COUT 6
VCC
ExtG n
GATE n
(2) Jumper installed : Cascaded gate control
/COUT 6
VCC
Figure 2.14 Gate source of counter #1 ~#4
The jumper setting is flexible for users‘ applications. There are two
configurations: jumper installed or NOT installed. The default state of
jumper is not installed and the counter can be controlled externally or just
pull-high enable. When the jumper installed, the gate is cascaded from
counter #6 output and the ExtG n signal is an output signal.
Note that the external gate source must NOT be used when cascaded gate
source is used. Table 2.5 shows the reference number of the gate control
jumpers and its corresponding counter/timer channels number. The default
setting of every jumper is also shown.
Jumper Label Gate source of counter/timer Default gate ource
G1 GATE1 ExtG1
G2 GATE2 ExtG2
G3 GATE3 ExtG3
G4 GATE4 ExtG4
Table 2.5 Reference number of clock setting jumpers
2.11 Counter Outputs