SI-H Muscle Testers
20
WORLD PRECISION IN STRU MENTS
the motor so that the sarcomere length is held constant while trying to study true
isometric contractions
•
Bypass
–In this mode, the Constant Load Module is completely bypassed.
Bypass Motor Command
received from
LabTrax 8/16
Command sent
to
Linear Motor
To use Bypass Mode, send a continuous voltage of at least 3.0V from one of the ana-
log or digital outputs of the
LabTrax 8/16
to the
CL Bypass
inputs of the
SI-COLUB
.
In this mode, the motor is moved by connecting the analog position protocol output
of the
LabTrax 8/16
to the
Bypass MOT CMD
of the module. The signal in the posi-
tion protocol programmed by
MDAC
will drive the motor when the
MOT POS CMD
OUT
is connected to the
Position In
of the
SI-MOTDB Motor Controller
.
IMPORTANT NOTE
: THE
SI-COLUB
unit can only be used on tonically contracting muscle
tissue (for example, during a tetanic contraction). For equivalent experiments in cardiac
muscle and skeletal twitch contractions, the AFTERLOAD unit is needed. Contact WPI for
further information.
Force Step Dial
Restretch Potentiometer (Restretch)
External Command Toggle Switch (EXT CMD/CL)
Slack Potentiometer (Slack)
Stretch Control Knob
Capture BNC (CAPTURE)
Alternate Feedback BNC (ALT FB)
C
A
Bypass Motor Command BNC (BYPASS MOT CMD)
Motor Position Command Output BNC (MOT POS CMD OUT)
Constant Load Bypass BNC (CL BYPASS)
B
B
M
M
Constant Load Command BNC (CL CMD)
Fig. 20 The SI-COLU Constant Load Module can be used to switch from an isometric to an
isotonic contraction by engaging a feedback around a reduced constant measured force.
