Axis 670 Bedienerhandbuch PDF herunterladen (Seite 19)

3.13.

Protection Circuits

The 670 board has various protection features, some of wiiich have been mentioned above. The

primary purpose of

this

circuitry is to allow the servo to stabilize in a contiolled fashion during

startup, and to shut down the scanner in a confrolled maimer should it detect any error conditions

that could damage the scanner.

The 670 system has two output signals that allow the user to monitor system status. One is the

"FAULT OUT" signal available on the J4.7, and tiie otiier is the "90% Max Power Warning"

signal available on

J4.6.

Use J4.5 for the ground retum. These are open collector switches that

pull down to -15v when active, and have a IK ohm output impedance. The ciurent sinking

capability of

these

outputs is lOma. The LED Status Indicator on the board tums red whenever

the board is in the fault condition.

3.13.1.

Startup Sequence

During a normal startup the fault detector U8 goes into an error or "fault" state. This causes the

following:

The output amp is disabled via U15A, effectively disconnecting the scanner coil from the

servo amp.

The summing amplifier gain is reduced by a factor of 100 via U15C and R35, allowing a

very small ertor signal to be sent to the output stage.

The "command in" signal is disabled via

U15B,

reducing the command input to zero.

The "fault out" signal on J4.7 is active, and the LED status indicator glows red.

After

second, the first stage of U8 resets and following actions occur:

The output amp is enabled, allowing current from the output stage to pass through scanner.

The summing amplifier

enabled and the FET across it tums off slowly so that the gain

in the summing amplifier slowly increases.

The "command

in"

signal is still disabled.

The above actions cause the scanner to center itself in a contiolled way, but prevents the

scanner

from

being driven

v^diile

doing so.

The "fault out" signal stays active with the status LED red.

1 2 ... 14 15 16 17 18 19 20 21 22 23 24 ... 67 68

Kommentare zu diesen Handbüchern

Keine Kommentare

Axis 670 Bedienerhandbuch Seite 19

Kommentare zu diesen Handbüchern

Verwandte Produkte und Handbücher für Drucken & Scannen Axis 670