Tech Notes
Tech Notes
Quick Start
Cabling and Connectors
Connectors and Pinouts
Mounting the Drive Unit
Completing Connections
Using the Drive
Data Compression Operation
Loading/Unloading a Cartridge
Unloading a Cartridge Manually
Using a Blank Cartridge
Using a Cartridge Containing Data
DAT Cartridge
Write Protect Tab
Maintaining the Drive
Head Cleaning
Quick Start
1. Set operational jumpers.
2. Install the drive.
The drive can be installed either horizontally or vertically.
3. Install the power and data cables.
NOTE: Turn off all power before inserting connectors. Pin 1 on the SCSI connector is to the right while looking at the back of the drive. The SCSI cable should have pin 1 highlighted by a color strip. Be sure to match pin 1 on the cable to pin 1 on the drive, otherwise the drive may be rendered inoperative.
Cabling and Connectors
The CTD8000 DDS-2 drives provide standard, single-ended SCSI transmission. ANSI SCSI standards specify the technical requirements for correctly cabling and connecting single-ended devices.
Either 50-pin flat cable or 25-signal twisted-pair cable with a maximum length of 6 meters (19 feet) may be used to connect the CTD8000 drive to its SCSI host adapter output. If twisted-pair cabling is used, connect the twisted pairs to physically opposing contacts on the connector.
Connectors and Pinouts
The CTD8000H-S and CTD8000R-S internal drives provide a 50-pin, right-angle, dual-row connector on the main PCB at the rear of the unit. The pin assignments for this single-ended connector are listed in the following table.
Note: All odd pins except pin 25 are connected to signal ground at the drive. Pin 25 is left open. A signal name or abbreviation preceded by a  (dash) indicates that the signal is active-low.
Pin Assignment
2 -DB (0)
4 -DB (1)
6 -DB (2)
8 -DB (3)
10 -DB (4)
12 -DB (5)
14 -DB (6)
16 -DB (7)
18 -DB (8)
20 GROUND
22 GROUND
24 GROUND
26 TERMINATOR POWER
28 GROUND
30 GROUND
32 -ATN
34 GROUND
36 -BSY
38 -ACK
40 -RST
42 -MSG
44 -SEL
46 -C/D
48 -REQ
50 -I/O
The +5V drive supply is available on the SCSI connector as a terminator power option. This pin is connected to the +5V through a diode. The option is a hardware jumper on the rear of the internal drives with terminator power disabled as a factory default.
ANSI defines -RST as a bidirectional pin. On the CTD8000 drive , -RST is input only.
Mounting the Drive Unit
The CTD8000R-S internal drive can be installed in 3 different orientations: 1 horizontally (eject button right) and 2 vertically (eject button up or eject button down).
The CTD8000R-S drive chassis contains threaded mounting holes for M3.0 metric screws. The maximum length for the M3.0 screws is 4 mm. Use of longer length screws may damage the drive. 4 are located on the bottom, and 6 are on each side of the frame.
Completing Connections
The power and interface connectors for the CTD8000R-S internal drives are located at the back of the drive unit
Back of the Drive Unit
 .
Turn off all power before inserting connectors. Pin 1 on the SCSI connector is to your right as you look at the back of the drive. Your SCSI cable should have Pin 1 highlighted by a color strip. Be sure to mate Pin 1 on the cable to Pin 1 on the drive. Failure to do so could make the drive inoperative.
The recommended power mating connector requires an AMP 1-48024-0 housing with AMP 60617-1 pins or equivalent.
Using the Drive
Data Compression Operation
Default operation for the CTD8000 drives is with data compression enabled  The drive automatically compresses all data written to tape and decompresses all compressed data read from tape, in DDS-DC format. Data with high degrees of redundancy, such as structured database files, can be compressed most efficiently, often at a ratio of 4:1 or more. Data with little redundancy, such as executable programs, can be compressed least. Total system throughput also affects tape capacity when compressing data.
To software-switch between compressed mode (writing compressed data, DDS-DC format) and noncompressed mode (writing uncompressed data, DDS format), the host computer executes a SCSI MODE SELECT command.
On internal CTD8000 drives, a jumper on the rear panel can also be used to enable or disable data compression.
The SCSI MODE SELECT command can switch the CTD8000 drive into compressed or uncompressed mode for writing data regardless of the position of the jumper position. When reading, the drive automatically selects compressed or uncompressed mode depending on the data being read.
Loading/Unloading a Cartridge
The CTD8000 drives have a front-loading cartridge insertion mechanism that allows the operator to easily load the cartridge by pushing against the middle part of the cartridge opening until it is fully recessed into the cartridge insertion slot. Insert the cartridge with the arrow on the top of the cartridge entering the slot first.
You unload the cartridge by pressing the eject (tape unloading) button on the front panel. Once you press the eject button, the CTD8000 drive updates the system log with a running count of drive/tape "soft" errors, rewinds the tape, and then ejects the cartridge. It is partially ejected and can then be easily removed from the drive.
Under a few exceptional conditions, such as a power outage, you may need to manually unload a cartridge. See emergency eject procedures.
Note: The time between pressing the eject button and cartridge ejection may be several seconds. Do not power down the external drive or the internal drive host computer during this time.
Unloading a Cartridge Manually
Access for Manual Cartridge Unload
1. Remove the drive from the computer
2. Remove the mounting rails. First remove the thin outer rails, then remove the large box shaped rails by removing the mounting screws that are accessed through holes in the side of the unit.
3. Remove the top cover of the drive by removing the 2 screws at the top edge near the rear of the unit (1 on each side.). See C on Locations on the drive unit
4. Remove the front bezel by pulling out on the top of the bezel at the indentation. See B on Locations on the drive unit
5. Insert a small, precision screw driver in the hold on the right side of the drive and turn the mode motor shaft clockwise. See C on Locations on the drive unit and Close up of Manual Cartridge Unload Switch.
Locations on the Drive Unit
Close up of Manual Cartridge Unload Switch
Caution: Do NOT turn the mode motor shaft counterclockwise. This could damage the mode gear.
6. Continue turning the mode motor shaft clockwise and the you will see the cartridge slowly rise. The metal track marked as A in Removing a Cartridge slowly moves forward changing the cartridge position as you continue turning the shaft clockwise.
Continue turning the shaft until the cartridge rises and then protrudes from the slot and clicks free. Remove the cartridge.
Using a Blank Cartridge
When you insert a blank DDS-2 or DDS cartridge into the CTD8000 drive for the first time, it is automatically initialized. The CTD8000 drive first detects that the tape is blank (about 10-12 seconds). It then initializes the tape when it receives a command that causes writing to the tape.
Note: Initializing the tape takes about 30 seconds. Ejecting the cartridge before the initialization is completed causes the procedure to abort. The initialization then restarts from the beginning the next time a WRITE command is received.
If the first WRITE command stores less than 126 kilobytes of data, the data is placed in the buffer until the next WRITE command exceeds the 126-kilobyte buffer capacity and forces the stored data to actually be written to tape.
The following steps outline a typical sequence for using a blank cartridge.
1. Gently push the blank DAT cartridge into the cartridge insertion slot on the front panel with the arrow on the top side of the cartridge entering the opening first.
Once the cartridge is partially inserted, the drive mechanism automatically completes the cartridge insertion and proper positioning.
The yellow and green rectangular LED's on the front panel go ON as the drive checks the cartridge to determine its state (blank, write-protected, prerecorded audio, firmware update, and etc.) and positions to the data area, which takes about 10-12 seconds.
2. Start the software application and issue a command.
For example, if you want to back up a file, issue the appropriate command or make the appropriate menu selections from backup application software. The CTD8000 drive begins initializing the tape before completing the backup (WRITE) operation. WRITE operations are completed during the initializing operation without delay until all internal buffers are filled.
3. After completing the backup and after the yellow rectangular LED on the front panel is OFF, push the eject (tape unload) button on the front panel to remove the cartridge. The CTD8000 buffer is then emptied to tape, and the tape is rewound.
The CTD8000's data buffer is also emptied to the tape in these 3 cases:
A REWIND command is issued.
The eject button is pushed.
A delay as defined by MODE SELECT or the 1-minute default delay time in which no activity occurs.
Before the CTD8000 drive ejects the cartridge it automatically updates the system log, which requires a few seconds; then it rewinds and ejects the cartridge. When ejected, the cartridge is pushed out of the cartridge insertion slot to a half-way position for easy removal.
Using a Cartridge Containing Data
The sequence for writing a cartridge that already contains data is similar to the blank cartridge sequence except the cartridge is not automatically initialized by the drive. A brief delay occurs when the cartridge is first inserted as the CTD8000 drive identifies the cartridge type and state, and positions to the data area.
DAT Cartridge
The CTD8000 products are designed to use data-grade DDS DAT cartridges, which comply with the specifications in the 3.81 mm Helical-Scan Digital Computer Tape Cartridge for Information Interchange, ANSI X3B5/89-156 standard. Conner recommends Conner-qualified, data-grade DDS DAT cartridges (Model M31300, 60 meters; Model M32000, 90 meters; and Model 34000, 120 meters) to ensure optimal data integrity and reliability.
Conner also recommends the use of an Conner-qualified DDS DAT head-cleaning cartridge (Model M7301).
Note: Proper maintenance of the CTD8000 drive requires that the DDS head-cleaning cartridge be used every 25 hours of read/write operation and whenever the rectangular, green cartridge-in-place LED flashes during operation.
Both DAT data and head-cleaning cartridges can be ordered from Conner.
Qualified DAT cartridges are designed with specific file protect, lid, and other features for information interchange and are tested to comply with the ANSI DDS specifications.
The CTD8000 drives also recognize 120 meter MP+ cartridges and other MRS cartridges when MRS is enabled. MRS cartridges have a series of alternate opaque and clear stripes at the beginning of the tape. This stripping classifies the media as data grade, rather than audio grade media. 4 recognition holes allow the drive sensors to identify the type of tape, its magnetic thickness, and to determine whether the tape is prerecorded or unrecorded or is a cleaning cartridge. Other cartridge features to allow the drive to optically sense "cartridge in", BOT, and EOT.
Write Protect Tab
The sliding write protect tab on the DAT cartridge and its positions for write protect and write permit. When the tab is pushed into the closed position, it allows writing to the cartridge tape.
Maintaining the Drive
If excessive magnetic dust or debris collects at 1 or more of the heads, magnetic media may become unreadable or unwritable. This situation may occur infrequently, or not at all, depending on the media used.
Head Cleaning
Whenever the Cartridge In Place status LED (green) flashes, you should clean the drive heads with a cleaning cartridge.
Also, as routine maintenance, the drive heads should be cleaned after the first 4 hours of tape movement of a new cartridge and thereafter after every 25 hours of read/write operation.
Note: The slowly flashing green LED may also refer to a damaged tape or a tape nearing the end of its life. If cleaning the head does not correct the flashing LED condition, replace the cartridge. The slowly flashing LED does not indicate a loss of data nor does it affect SCSI operation. (A slowly flashing green LED in conjunction with the yellow LED indicates the presence of a prerecorded audio tape.).
To clean the heads of the CTD8000 drive, use only an Conner-qualified DDS DAT cleaning cartridge designed for DDS drives. Conner offers a cleaning cartridge, Model M7301.
The DDS cleaning cartridge contains the correct recognition holes to allow the CTD8000 drive to recognize that it is a cleaning cartridge.
To use the cleaning cartridge, insert the cleaning cartridge. The CTD8000 immediately detects that the cartridge is a cleaning cartridge.
The drive loads and runs the cartridge for about 30 seconds; then ejects the cartridge.
Note: Each time the cleaning cartridge is loaded, a new, unused portion of cleaning tape is advanced over the entire tape path. Eventually, the entire tape is used, and a new cleaning cartridge is required. (A cleaning cartridge provides approximately 30 uses.) The CTD8000 drive will not rewind the cartridge.
Do not use an audio DAT cleaning cartridge. It will not be properly recognized by the CTD8000 drive.
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