QTech Q23, Owner'S Manual, Page: 14 / 50

FUNCTIONALITY
Page 14 Q23 Expansion Module
❖
Digital output channels 5 to 8 are available at a 6 way connector labelled
‘AUX OUT’
on the bottom panel
of the Q23 Module. The digital output channels are numbered 5 to 8. The terminals labelled
‘+’
are
connected to the switched positive rail of the module’s power supply. Digital output channels 5 to 8 do not
have status LED indicators.
In the ON state a digital output channel is switched to ground. In the OFF state a digital output channel is open
circuited. The digital output channels are capable of switching 1 amp at up to 26.5 volts. The voltage into a digital
output channel when the channel is OFF is clamped to 65 volts. This eliminates the need for reversed biased
diodes across inductive loads.
Note The total switching current for all digital output channels is limited to approximately 1.5 amps by the Q23
Module internal 2 amp fuse.
The digital output channels have built in failsafe functions that protect and report digital output malfunctions. These
include:
Output Protection Each individual output circuit is protected against over-voltage at input voltages greater than
typically 28 to 36 volts with automatic shut down and soft restart when the voltage returns to normal.
Similarly each output has over-current shut down at typically 3 to 6 amps with additional over-temperature
shut down functions. (These functions make the outputs reasonably indestructible.)
Over-Current Recovery When jumper J28 is installed an over-current fault on any output channel will cause that
channel to turn OFF and remain OFF until the over-current fault is removed and the central processor
resets the channel by turning it OFF. This is the default configuration.
When jumper J28 is not installed an over-current fault on any output channel will cause that output channel
to go into current limit mode of approximately 0.5 amps. The output channel will return to normal operation
when the over-current fault is removed, provided thermal shut down has not occurred.
Open Circuit Detection When the output channel is turned OFF a sensing current of approximately 50uA flows
through the load and is used to detect open circuited loads.
Failsafe Fault Reporting
The open circuited load, short circuited load, over-current, over-voltage and thermal shutdown faults are reported
back to the central processor. These failsafe faults can be forwarded to other modules or remote base stations.
On output channels 1 to 4 any of the above faults will cause the associated yellow status LED to flash indicating a
channel fault.
Analog Inputs
The Q23 Module has 6 Analog input channels. These are available at a 9 way connector labelled
‘ANALOG I/O’
on the front panel of the Q23 Module. The Analog channels are numbered 1 to 6. The terminal labelled
‘G’
is a
system ground connection. The terminals labelled
‘+’
are connected to the switched positive r
ail of the module’s
power supply. Each Analog channel has an associated yellow status LED to show the state of the Analog channel.
Note Analog channels 5 & 6 can be configured individually as either input or output channels.
Each yellow status LED shows the following channel status:
OFF Indicates that the Analog input is at 0V/0mA dependent upon the input mode configured. Or less
than 4mA in 4 to 20mA current input mode.
ON Indicates that the Analog input is within the specified voltage or current range dependent upon the
input mode configured.
FLASHING Indicates that the Analog input is at full scale input of 5V/10V/20mA or higher dependent upon the
input mode configured.
The Q23 Module’s 6 Analog channels can each be individually configured as single ended voltage or current
inputs. Channels 1 & 2 and/or 3 & 4 can be configured together to form 2 differential voltage or current input
channels.
NOTE: Single ended input means that the input voltage or current is referenced to ground. That is the negative
side of the input is at ground (earthed) potential. (The
‘G’ terminal on the Analog front panel connector.)
Differential Analog inputs provide for none ground referenced negative inputs and provide up to 10 volts
common mode rejection on Analog input signals.
Differential inputs can also be used for 20mA current loop applications allowing the Q23 Module to be
included in a multi-drop 20mA current loop application.