FIELD EXERCISER FUNCTIONS AND OPERATION

5.5.1 GENERAL DESCRIPTION

The WANGCO Field Exerciser (WANGCO PIN :300382) is an economical off-line test device that provides manual and automatic control of the ReadlWrite positioning servo in both the Series F and Series T Disc Drives. The Field Exerciser plug-in unit is used in the alignment and calibration procedures. It also may be used within limitations in off-line trouble diagnosis of the positioning servo electronics. The Field Exerciser will not re!ad or write any data patterns, and for this reason, cannot be used for diagnosis procedures requiring comparison.

The Field Exerciser components are mounted on a printed circuit board which is inserted in

location J1 in the card cage when the Data Interface Board has been removed. It is fully operational when it has been inserted in its receptacle and power is applied to the Disc Drive. Installation of

the Field Exerciser automatically puts the Disc Drive in off-line operation since removal of the DI B interrupts the I/O lines to the remote controller.

The Field Exerciser circuitry is implemented with TTL integrated circuits. Its various functions are programmed and activated by means of eight switches which are mounted along the upper edge of the board. Head position is indicated by-'nine CYLINDER ADDRESS lights mounted below the control switches. Two test points (SEEK COMPLETE and INDEX) and a SEEK COMPLETE indicator lamp also are mounted on the circuit board. See Figure 5-28 for a line drawing of the Field Exerciser Board.

5.5.2 OPERATING CONTROLS - FIELD EXERCISER

5.5.2.1 RESTORE (S1). A momentary-contact pushbutton switch which initiates a Restore operation.

5.5.2.2 DISC SELECT, REM/FIX (S2). A two position toggle switch that selects either the head pair associated with the cartridge disc or the head pair associated with the fixed disc.

5.5.2.3 HEAD SELECT, TOP/BOT (53). A two position toggle switch that selects the upper or lower head of the head pair selected by switch 52.

WAN-0048/2A-001

CYLINDER ADDRESS

256 128 64 32 16 8 4 2 1 OSlO TP3

«J «J ~ ~ ~ ~ ~ «J «J «JSKCOMP ~GNO

~~~2rr ~~~~5~~~ B ~~~~~0~O~~~~~ B

Figure 5-28. Field Exerciser Controls, I ndicators and Test Points

5.5.2.4 100/200 TPI (S4). A two position t~ggle switch that selects access of 200 or 400 tracks depending on whether the Field Exerciser is using a 100 or 200 tracks-per-inch unit.

5.5.2.5 I NC/F I X/DEC (S5). A three position toggle switch which selects the positioning mode. I n the I NC position, the Field Exerciser programs the positioning servo for successive incrementing of the heads, one track at a time, in the forward direction (toward the innermost track). In the DEC position, the heads will decrement, one track at a time, in the reverse di-rection (toward track 000). In the FIX position, the positioning servo will keep the heads over a given track. The access speed is governed by the setting of switch S6.

5.5.2.6 ALT, OFF/ON (S6). A two position toggle switch which enables the servo to alter-nate between track 000 and any selected track. When switch S6 is in OFF position, the access mode is governed by the setting of switch S5. When switch S6 is in ON position, the head carriage will travel, in alternating fashion, from a track accessed by switch S5 to track 000 and then back to the selected track, etc.

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5.5.2.7 AUT/MAN (S7). A two-position tO~J9le switch which selects automatic or manual operation. With,switch S7 in the AUT position, the accessing mode, selected by switches S5 and S6, proceeds automatically and is synchronized to the Index pulses. When switch S7 is in the MAN position, the accessing mode selected will be un~er control of switch S8 the START push-button switch.

5.5.2.8 START (S8), A momentary-contact pushbutton switch which initiates the accessing operations. It operates in conjunction with switch S7.

5.5.3 INDICATORS AND TEST POINTS - FIELD EXERCISER

The nine indicator lights located below the control switches signal the track position (cylinder address). The readout is in binary format. The indicator lamp above TP1 furnishes a SEEK COMPLETE indication.

Test point TP1 (Seek Complete) permits convenient measurement of access time. Test point TP2 (Index) permits oscilloscope synchronization to the Index Pulse. Test point TP3 is the circuit ground connection.

5.5.4 INSTALLATION -- FIELD EXERCISER

To install the Field Exerciser, perform the following steps:

A. Turn off power to the Disc Drive.

B. Extract the Data Interface Board (DIB) from its receptacle (refer to paragraph 5.4.3.14).

C. Insert the Field Exerciser board into the DIB connector location J1. Both the D I B and the Field Exerciser arE~ keyed so that when the Field Exerciser board is installed correctly, the controls and indicators face the positioner assembly.

5.5.5 OPERATION - FIELD EXERCISER

Select the disc (cartridge or fixed) to be read out with switch S2. Select the upper or lower head for that particular disc with switch S3. Select the. appropriate tracks/inch access with switch S4.

The programming of the accessing mode is illustrated in the following:

For example, if a 64-track seek is to be implemented, perform the following steps:

A. Place switch S6 in OFF position.

B. Place switch S5 in I NC (increment) position.

C. Place switch S7 in AUT (automatic) position.

D. Press and release switch S8 to indicate a Seek operation.

E. When the address indication of 64 is obtained, place switch S5 in F IX position;

the positioner carriage will stop at this track position (cylinder address).

An alternate mode can now be implemented by placing switch S6 in ON position. The positioner carriage will now extend to track position 64. It will then retract to track 000, again access to track 64, etc.

In another example, the mode is to be changed to a OOO-track 50 alternating access. In this case, stop the. process at cylinder address 64 by switch ing S6 to the 0 F F position. Next, decrement to track 50 by placing switch S7 in MAN position, switch S5 in DEC position, and press and release switch S8 until address 50 is obtained. Then return switch S5 to F IX position, switch S6 in ON position, etc.

5.5.6 BENCH EXERCISER FUNCTIONS AND OPERATION

Since the Field Exerciser is incapable of Read, Write, and Compare operations, the WANGCO Bench Exerciser (Part Number 300303-002) may be used in conjunction with the Disc Drive to simulate signals from the Controller or Formatter. It also may be used to initiate a Seek operation and to cause the unit to write on, and read from, the disc. Jacks mounted on the front of the Disc Exerciser provide a means of monitoring the signals generated in response to the Disc Exerciser program. Refer to the Operation and Maintenance manual for the Disc Exerciser (300880) for instructions on operation of the Disc Exerciser.

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