Activation Command Sensing; Automatic Return Monitor (A.r.m.); System Controllers And Monitor; Low Voltage Power Monitoring - ConMed Sabre Genesis Service Manual

3.2.4

Activation Command Sensing

Each of the Hand Controlled Accessory recep-
tacles incorporate inputs that are used to sense
an activation command from the user. Each
monopolar hand controlled accessory receptacle
has an input for Cut and an input for Coag. The
bipolar receptacle incorporates a single activation
input. Each of these five inputs is isolated from
the other electrosurgical outputs and from other
low-level circuitry in the system. All are powered
by a multiple output isolated power supply. The
footswitch activation inputs on the back panel are
configured in a similar way and share one of the
isolated power supply outputs.
3.2.5

Automatic Return Monitor (A.R.M.)

The patient return connector interfaces to single
and dual dispersive electrodes using a two-pin
connector. A.R.M. circuitry uses an actively driv-
en impedance measurement circuit, which allows
the System Controller to detect the type of disper-
sive electrode connected and verify its integrity.
3.2.6

System Controllers and Monitor

Two processors and an FPGA are used for system
interface & control, RF control, and system moni-
tor functions. The RF control section consists of
a dual-channel architecture with two independent
channels where one is used exclusively for RF out-
put control and the other is used for safety moni-
toring. All of these elements are located on the
Control board, along with circuitry for interface
with the user.
• System Controller (System Microcontroller):
A dedicated Microcontroller that handles
the entire user interface, Serial Interface, and
enables/disables the power factor control sec-
tion of the RFPS using the PFC_EN signal.
The System Controller can also disable the
signal used to drive the RF Amplifier and can
terminate RF drive at any time without inter-
action from either the RF Controller or the
Monitor. The System Controller is comprised
of a standard architecture microprocessor
together with portions of the FPGA, which
provides interface logic to a variety of signals,
independent voltage regulators, a processor
supervisory reset circuit, and other interface
logic.
• RF Controller: An FPGA implementing
digital signal processing elements for control
of RF power using the VBASE_PWM and
RFGATE outputs. To reduce the effects on
the microprocessor circuits on the Control/
Display Board from RF noise at the output,
VBASE_PWM and RFGATE are both dif-
ferential mode signals running between the
Control/Display Board and the power section.
The RF Controller is capable of disabling
RF output power and putting the system
into a safe state without any interaction from
the Monitor or the System Controller. The
RF Controller independently monitors the
RF output voltage and current for control
purposes through several scaled inputs. The
RF Controller is comprised of the major por-
tion of the FPGA, together with circuitry
necessary for converting the control signals
between analog and digital form.
• RF Monitor: A DSP that is dedicated to safety
monitoring activities. The Monitor is capable
of disabling RF output power and putting the
system into a safe state without any interac-
tion from the RF Controller or the System
Controller. To ensure that the Monitor can
correctly perform its function, the Monitor is
resistively isolated from the System Controller
and the RF Controller and has independent
voltage regulation. The RF Monitor indepen-
dently monitors a variety of inputs to detect
safety problems and has control of disable
signals for RF Amplifier drive. The Monitor
is comprised of a DSP , together with circuitry
necessary for converting the signals monitored
between analog and digital form, an FPGA to
provide interface logic, independent voltage
regulators, isolation resistors and other inter-
face logic.
3.2.7

Low Voltage Power Monitoring

The low voltage power supply is monitored in
hardware and resets the processors if it is out of
range. The microprocessor supervisory device on
the Control/Display Board monitors +3.3V and
+1.8V and will reset the system should the levels
drop approximately 0.3V . The Control/Display
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