Scan and Blank settings
Microscope needs to be informed when an external scan signals wishes to take control over the scan. For this purpose, two signals are provided to the microscope
- Scan output - a hardware trigger to the microscope to request switch from internal to external scan
- Blank output - a hardware trigger to the microscope to switch off (blank) its display.
In addition, the microscope may only provide one external scan input interface, but two or more external scan controllers must be connected to the microscope. For this case, the scan controller provides an additional scan input with an automated internal scan switch, which allows for daisy-chain connections. A daisy chain configurations connects all the scan controllers in series, with inactive controllers passing trough the signals directly from scan input to scan output, so that the active scan controller has access via multiple passive controllers to the external scan interface of the microscope.
Change of these settings require access to a number of internal jumpers for configuration. Jumpers are preferred method for configuration if changes in configuration may break compatibility or damage other equipment, and therefore changes are not intended for end users, but intended for service engineers only. These jumpers are normally configured in production for the intended microscope, and do not require change in the field unless it must be installed or moved to a different microscope type.
Risk of death by electrocution!
The device must be open to gain access to the internal jumpers - follow instructions from the Hardware Reference manual supplied with the hardware.
To access the control logic with the Scan Control app, see the Scan and Blank buttons in the Triggers toolbar.
Internally generated
Internally generated Scan and Blank signals are sourced by the scan controller. This assumes no connection to the Scan Input - for daisy chaining, else see following section.
As different microscope models require different Scan and Blank signals levels, these may be configured with internal jumpers individually to
- Ground (GND)
- +5V
- +15V
Logic of these two signals is not fixed, and it may be inverted in the firmware. For example, if Scan is configured via its jumper for GND, then
- when a scan job is
running in the scan controller, then Without inversion, internal Scan signal (GND) will be output
- Without inversion, no output
- With inversion, internal Scan signal (GND) will be output
Externally generated
Externally generated Scan and Blank are signals not sourced by the scan controller, but generated by another external scan controller and passed through this scan controller from scan input to scan output as part of a daisy chained configuration. Logic of passthrough may be configured with internal jumpers, see list below, and further logic is added by the Scan and Blank inversion controls.
Internal jumpers for externally generated Scan and Blank signals may be set to
- Shield Ground (Sh. GND)
- Normally Closed (NC)
- Normally Open (NO)
If Shield Ground is used, then external Scan and external Blank signals are connected to ground and the passthrough is deactivated.
Normally Closed scan switch logic is typical for daisy-chaining, where
- When a scan job is not running in the scan controller, then
- Without inversion, external Scan and Blank will be output (passthrough)
- With inversion, internal Scan and Blank will be output
- when a scan job is running in the scan controller, then
- Without inversion, internal Scan and Blank will be output
- With inversion, external Scan and Blank will be output (passthrough)
Normally Open scan switch logic shorts together external and internal Scan and Blank, respectively. Then
- when a scan job is not running in the scan controller, then
- Without inversion, no output on Scan and Blank
- With inversion, Scan and Blank will be output (passthrough)
- when a scan job is running in the scan controller, then
- Without inversion, Scan and Blank will be output (passthrough)
- With inversion, no output on Scan and Blank