Bi-directional Serial to Parallel Connverter RS Stock no. 199-2720 Introduction This device is a Bi-directional Converter which converts the Centronics type parallel to EIA-RS232/CCITT V.24 serial or vice versa. It will help you convert the data on the host transparently to meet the requirement of the peripheral. Although this device is workable on its CPU's 88 bytes RAM, memory expansion is easy-simply plug a 8/9-bits SIMM 256K/1MB into its internal SIMM socket. Overview PWR STS P.B. S.D.
DIP DC DTE/DCE Centronics 36 RS232C Switch Power Switch Female DB25 Female jack Table 1: 10-bit Dip Switch Setting #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 0 0 No flow control 0 1 Software flow control, Xon/Xoff. 10 .Hardware flow control, RTS/CTS 1 1 Test Mode, factory use only 0 0 0 110 bps. 1 0 0 300 bps. 0 1 0 600 bps. 1 1 0 1200 bps. 0 0 1 2400 bps 1 0 1 4800 bps 011 9600 bps 1 1 1 19200 bps. 0 7 data bits 1 8 data bits 0 0 None parity. 0 1 None parity. 1 0 Even parity. 1 1 Odd parity. 0 Serial to Parallel conversion. 1 Parallel to serial conversion. 0 Normal operation. 1 a.) Before power on: Enter self diagnostic mode. b.) After power on: Exceed 2 seconds will make copy start. c.) After power on: Exceed 6 seconds will reset Converter and clear buffer. * Bold italic means the default setting. * 0 means Off position and 1 means On position. Pre-Installation Procedure Before installing this device, you should check the specification of the ports on the host or peripheral which you are going to connect to-particularly the serial protocol. Write down the correct baud rate, data length, parity check, data flow control and DTE or DCE configuration of the serial port. You can not connect two ports with the same configuration by a pin-to-pin cable, as sometimes, it will damage both ports. Two cables are required to complete the installation. One is the serial cable. For instance you may require a DB-9-F to DB-25-M cable or a DB-25-F cable. As for the parallel cable, you also have two choices, one is the standard IBM printer cable (DB-25-M to C-36-M) and the other one is C-36-M to C-36-M pin-to-pin cable. Note: DO NOT connect a serial port to a parallel port directly. Damage may be caused. Installation Before installation, you should have all the protocol information and two necessary cables. 1. Power off all the devices which you are going to connect to. 2. Choose one direction of the data flow and set up the serial protocol according to your collected information. Please refer to table 1 for the dip switch settings. 3. Install the serial cable and parallel cable securely. 4. Slide the DTE/DCE switch to the opposite setting of the serial cable end. A DTE device (Data Terminal Equipment) can only communicate to a DCE device (Data Communication Equipment). 5. Plug the mains adaptor (RS stock no. 593-502) 9Vdc plug into the dc jack (inner polarity is positive) on the converter and then plug into the mains. The converter's PWR (Power) LED will light. Wait until the self-quick-test is complete-the STS (Status) LED will indicate the memory size test result and then enter the standby state.
Figure 1 DC power plug type and polarity
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6. Turn on the peripheral and then the host. Memory Expansion Procedure Select a SIMM (Single In-Line Memory Module) which conforms to the specification as appendix A. If there is no SIMM installed, the internal mini-jumper JP1 should be set off to activate the CPU's internal RAM. 1. Turn off the power to the converter and disconnect all the cables from the converter. 2. Unscrew the 4 bottom screws and then open the upper case. 3. Align pin # 1 of both the SIMM and socket. Gently insert the SIMM into socket at about 60 degree direction, and then push it over to the 90 degree position. 4. Set JP1 to the On position. 5. Replace the upper case and fasten all the 4 screws. 6. Reconnect the power to the converter and check the dip switch setting (refer to table 1). The result of the power on quick-test will flash the STS LED to show you the memory size. Technical specification
Power supply ______9Vdc 200mA adaptor (RS stock no. 593-302 see figure 1 for plug type) Buffer RAM sizes a.) ______88 bytes without SIMM (Internal JP1 Off) b.) ______normal 8/9-bits SIMM 256K or 1M bytes (Internal JP1 On) (The access speed of DRAM can be 60 ns to 150 ns on the SIMM) Serial interface a.) ______Asynchronous RS-232 compatible b.) Baud rate: ______from 110 bps to 19200 bps. See table 1 c.) Data bits: ______7,8 bits d.) Parity check: ______None, odd, even e.) Flow control: 1.______> None 2.______> Hardware, RTS/CTS 3. ______> Software, Xon/Xoff f.) DTE/DCE: ______Slide switch selectable g.) Connector: ______D-SUB 25-pins female Parallel interface a.) ______Centronics compatible, TTL level b.) Handshake : ______/Strobe, Busy,/Acknowledge c.) Connector: ______Centronics D-Shell 36-pins female 4 LEDs indication 1.) PWR: ______Power condition indication 2.) STS: Status display: ______ standby ______ standby with data on the buffer ______
+ PIN NOMENCLATURE
VCC 1 A0-A9 Address Inputs CAS 2 CAS Column DQ1 3 AO 4 Address Strobe A1 5 DQ2 6 DQ1-DQ8 Data In/Data A2 7 out A3 8 VSS 9 NC No Internal DQ3 10 A4 11 Connect A5 12 RAS Row-Address DQ4 13 A6 14 Strobe A7 15 DQ5 16 VCC 5-V Supply A8 17 VSS Ground A9 18 NC 19 DQ6 20 W 21 VSS 22 DQ7 23 NC 24 DQ8 25 NC 26 RAS 27 NC 28 NC 29 VCC 30 +
a-1) Normal 9-bits SIMM for 256K and 1M
PIN NOMENCLATURE A0-A9 Address Inputs VCC 1 CAS 2 CAS Column DQ1 3 AO 4 Address A1 5 DQ2 6 CAS 9 Strobe A2 7 DQ1-DQ8 Data In/Data A3 8 VSS 9 out DQ3 10 A4 11 D9 Data In A5 12 DQ4 13 NC No Internal A6 14 A7 15 Connect DQ5 16 A8 17 Q9 Data Out A9 18 NC 19 RAS Row-Address DQ6 20 W 21 Strobe VSS 22 VCC 5-V Supply DQ7 23 NC 24 VSS Ground DQ8 25 Q9 26 W Write Enable RAS 27 CAS9 28 D9 29 VCC 30 Appendix B Centronics parallel interface, C-36 Female connector. Pin Mnemonic Input #1 I/O Output I/O 1 /STROBE I O 2-9 DO~D7 I O 10 /ACK O I 11 BUSY O I 12 PE 270PL #2 270PL 13 SELECT 3.3K PH #3 3.3k PH 14 /AF 3.3k PH 3.3k PH 15 NC #4 16-17 GND 0V 0V 18 +5V 330PH 330PH 19-30 GND 0V 0V 31 /INIT 10k PH 10k PH 32 /ERROR 10k PH 10k PH 33-34 GND 0V 0V 35 +5V 10k PH 10k PH 36 /SLCTIN 270 PL 270 PL Notes: 1. Input mode: dip-sw-9 On, Output mode: dip-sw-9 Off. 2. PL: Internal Pull-Lo resistor. 3. PH: Internal Pull-Hi resistor. 4. No connection. Appendix C RS-232C serial interface, DB-25 Female Connector Pin Mnemonic DTE DCE Description 2 TXD Out In Transmitted data 3 RXD In Out Received data 4 RTS Out In Request to send 5 CTS In Out Clear to send 6 DSR nc +9VPH Data set ready 7 GND 0V 0V Signal ground 8 DCD nc +9VPH Received line signal detector 9 +9V Out Out DC +9V power supply output 20 DTR +9VPH nc Data terminal ready. * The rest pins have no connection. * nc means no connection. * +9VPH means 470 OHMs pull-up to +9Vdc. Appendix D LED display description 1. PWR LED: Indicates power supply condition. 2. STS LED: Status display.
CYCLE n CYCLE n+1 ON OFF Standby Buffer has data Error
3. P.B. LED: Parallel busy status, on means busy (High), Off means not busy (Low). 4. S.D. LED: Serial data activity status, TXD and RXD wire-ored. Appendix E Self-diagnostic mode This converter has a self-diagnostic function to help you detect whether the RAM bits of the SIMM are valid or not. First turn off the power supply and disconnect all cables. Then set dip switch #10 into On position and then power up the converter; This converter will instantly enter the diagnostic test mode (LED switch off). This will take about 22 seconds for every 256K bytes. If the checked SIMM passes a memory size will be displayed through the LED flashes (refer the following table 2 and STS LED display). This test is loop repeated. To stop the test switch off dip switch #10. Table 2: LED flash times for the SIMM size indication Waiting time LED flash times Memory size 22 sec. 3 256K 44 sec. 4 512K 88 sec. 5 1M 176 sec. 6 2M 264 sec. 7 3M 352 sec. 8 4M
Diagnostic mode STS (status) LED display
ON STS OFF memory size 3 Power on 22 seconds for 256K LED pulses
RS Components Issued March 1996 10135