technical reference
3
28
Synrad
Firestar i401
operator’s manual
Integrating Firestar safety features
The
Integrating Firestar safety features
section includes subsections:
■
Keyswitch functions
■
Shutter functions
■
Remote interlock functions
Firestar’s DB-15
User I/O
connector allows system integrators or end-users to integrate Firestar safety fea-
tures into their control system. Firestar’s keyswitch, shutter, and remote interlock functions serve to enable
or disable DC power to Firestar’s RF drive. Without DC power, the RF driver cannot supply RF energy to
the resonator, causing the CO
2
gas to remain in a zero-energy state. Firestar status indicators provide users
with a quick visual indication of the laser’s operational status. All power to the laser’s RF board is removed
when the
RDY
indicator is Off (
Laser Ready
output open).
Keyswitch functions
OEM lasers
On OEM lasers, the
RDY
LED illuminates on DC power-up (when the
Remote Interlock
input is enabled)
and five seconds later, DC power is applied to the RF driver. When the
Shutter Open Request
input
is inactive (
SHT
indicator Off) only tickle pulses are applied to the laser. PWM Command signals are
enabled only when voltage is applied to both
Shutter Open Request
and
Remote Interlock
inputs (
INT
LED green,
RDY
LED On, and
SHT
LED On). Over temperature faults are reset by removing and then
re-applying DC power after the laser has cooled. Remote interlock faults are not latched; the
RDY
LED il-
luminates yellow as soon as the interlock circuit is closed (when the
INT
LED turns from red to green) and
five seconds later lasing is enabled.
Although a
Remote Reset/Start Request
input is not required to reset OEM faults, it can be used to
inhibit (disable) lasing. Disable the laser by applying a voltage in the range of ±5–24 VDC to Pin 2, the
Remote Reset/Start Request
input. Removing voltage allows power to reach the RF driver and begins
a five-second countdown after which lasing is enabled (
RDY
LED illuminates yellow). The RF driver is
disabled as long as voltage is applied to Pin 2.
Your control system can monitor the laser’s ready status on the
User I/O
connector by connecting your
system’s input between Pin 8,
Laser Ready
, and Pin 13,
Output Common
(see Figure 3-16).
The
Laser Ready
output closes when the laser is enabled (
RDY
LED illuminated yellow), indicating that
lasing is possible. The output is open (
RDY
LED off) when lasing is disabled.
Note:
After the
Laser Ready
output closes, a five-second delay occurs before lasing is enabled.
Shutter functions
An internal electromechanical shutter is installed on all i401 lasers. Lasing is enabled when the shutter is
open (
SHT
LED illuminated blue) and disabled when the shutter is Closed (
SHT
LED off).
For i401 OEM lasers in automated systems, shutter actuation is provided by the
Shutter Open Request
signal via Pin 10 on the
User I/O
connector. To use this feature, apply a voltage in the range of ±5–24
VDC to Pin 10,
Shutter Open Request
. This input signal causes the
SHT
LED to illuminate (provided
the
RDY
indicator is On) and opens the physical shutter to allow lasing. Removing voltage from the
Shut-
ter Open Request
input, causes the physical shutter to close and block the beam path, extinguishing the
SHT
lamp and allowing only tickle signals to reach the tube.
