High Country Tek emc-3L - Manual (Page 37)

Programming the Different Output Group Valve Configurations
Controlling valves has a few subtleties depending on the valve configuration. Some of the control of the valve’s
operation is done for you by the DVC710 BIOS. This level of BIOS control has two purposes. First, to ease
some of the application programming that would otherwise be required. Second and most important, is to insure
safe valve operation in the event of wiring or valve failure. You can think of this BIOS control as implementing
hidden code automatically for you.
Note: Should you inadvertently use a variable that is not defined for a particular valve configuration you will get a
compile error when you compile your application.
The default output group default variable names that control valves in Output Group 1 are:
HS_1
HS_2
PWM_1
PWM_1.Enable
PWM_1.Dir
For each of the five configurations a subset of these variables is used as enumerated below.
Dual Coil High Side (DCHS) in DVCH mode, the HS outputs are controlled by the BIOS
'Dual Coil High Side Control
PWM_1.Enable = Dig_1 '(if Dig_1 = True, then PWM_1 is enabled)
PWM_1.dir = Ana_1.dir '(set the PWM_1 direction bit to follow the Ana_1 direction bit)
PWM_1 = Ana_1 '(set the PWM_1 output to a linear relationship with Ana_1)
Single Coil High Side
'Single Coil High Side Control
PWM_1.Enable = Dig_1 '(if Dig_1 = True, then PWM_1 is enabled)
PWM_1 = Ana_1 '(set the PWM_1 output to a linear relationship with Ana_1)
HS2 = Dig_2 '(if Dig_2 = True, Then HS2 is turned on)
Single Coil Low Side
'Single Coil Low Side Control
PWM_1.Enable = Dig_1 '(if Dig_1 = True, then PWM_1 is enabled)
PWM_1 = Ana_1 '(set the PWM_1 output to a linear relationship with Ana_1)
HS1 = Dig_2 '(if Dig_2 = True, Then HS1 is turned on)
HS2 = Dig_3 '(if Dig_2 = True, Then HS2 is turned on)
High-Side Only
HS1 = Dig_1
'(if Dig_1 = True, Then HS1 is turned on)
HS2 = (NOT HS1) '(Set HS2 to the Compliment of HS1)
PWM Frequency
PWM_1.Enable = Dig_1
'(if Dig_1 = True, then PWM_1 is enabled)
PWM_1.Frequency = 80 '(Set the PWM Frequency to 80Hz)
pwm_1.dutycycle = Ana_1 '(set the PWM_1 DYCY to a linear relationship with Ana_1)
Open Detection
When using a PWM output to drive a ‘bang bang’ valve, be sure to set the max current in the output group to the
max current for the valve. The current feedback from the PWM output looks at the current. If the output is set to
2A, but the valve only uses 1.2A, then the controller sets the ‘open’ indicator and stops driving current.
P/N: 021-00163, Rev. A.0 - for V5.2 Tools Page | 37