Operating instructions

Table 2-7
EXT. CLOCK Pin Assignments
Pin No. Function Pin No. Function
1. REC TALLY 14. RWD SWITCH
2. PLAY TALLY 15. TACHO OUT
3. STOP TALLY 16. 9.6K REF.
4. FF TALLY 17. GND
5. RWD TALLY 18. EXT CLOCK (9.6 kHz nominal)
6. LIFTER DEFEAT 19. CAPSTAN TACHO OUT
7. SMPTE CUE 20. +5V (150 mA)
8. SPD REF. VOLT. 21. FWD/REV (Tape Direction)
9. SPD COM. 22. N.C.
10. REC SWITCH 23. N.C.
11. PLAY SWITCH 24. N.C.
12. STOP SWITCH 25. N.C.
13. FF SWITCH
2.4.4 Serial I/O Connector
The MTR-90 is provided with an interface function which enables direct
conversation with a computer. This function (SERIAL I/O) has the following
three capabilities.
(1) RS-232C
(2) CURRENT LOOP
(3) TTL LEVEL
The baud rate can be selected by the Dip Switches located on the I/O Control
PCB Assembly as given in Table 2-7.
Table 2-8
Baud Rate Settings
BAUD RATE SWI-1 SWI-2 SWI-3 SWI-4
110 baud ON OFF OFF OFF
1200 baud OFF ON OFF OFF
2400 baud OFF OFF ON OFF
4800 baud OFF OFF OFF ON
* Factory set to 4800 baud (SW1-4 ON) at the factory.
The SERIAL I/O connector should be connected according to Table 2-8.
Table 2-9
Serial I/O Connector Pin Assignments
Pin No. Function Pin No. Function
1. Frame GND 14. GND
2. Transmit Data 15. RD CNT
3. Receive Data 16. RD COM
4. RTS 17. TTY OUT
5. CTS 18. TTY IN
6. DSR 19. TTY COM
7. (sig) GND 20. DTR
8. GND 21. N.C.
9. RDR STA 22. N.C.
10. TXD 23. N.C.
11. RXD 24. N.C.
12. DATA BUSY 25. N.C.
13. DCD
For technical information about ASCII Command Characters List, contact
Otari or the local Otari dealer. The necessary connector is DC-25P (TRW
CINCH) or its equivalent.
Section 2 Installation
2 - 12
October 1990
MTR-90III Operation and Maintenance Manual