LT900SERIES. 1xN Multi-Channel Switch Operation Manual

Transcription

1 LT900SERIES 1xN Multi-Channel Switch Operation Manual

2 Table of Contents General Information.. 1 General Specifications Interface Connectors Connector Assignment 16 pin pin RS RS-232 Commands & Messages... 7 Operating Instructions 16 and 26 pin RS Micro-controller Interface Pin Function Definition Timing Diagram Testing Housing Drawing.. 15 Rev 0.0 i

3 General Information The LT900 Series 1xN optical switch module utilizes a high precision stepping motor to create a small multi-channel switch with low insertion loss and excellent repeatability. All LIGHTech switches feature our patented reflective optics technology, offering excellent optical performance and reliability from 0 to 50 ºC. LT900 Series 1xN Switch Common CH 1 CH 2 CH N-1 CH N Features Low insertion loss < 1.0 db Repeatability of < ± 0.02 db Available with 16-pin TTL, 26-pin TTL, or RS-232 control Co-positioning of all fibers and control connections on same end of module facilitate fiber management and maximize flexibility in board placement Applications Wavelength monitoring Optical system monitoring Optical test access OEM network test systems Network monitoring Network restoration Protection Optical Signal Switching Rev 1.1_09/2003 Page 1 of 16

4 General Specifications Parameter Typical Maximum Insertion Loss 1, db 1.0 db Back Reflection < -60 db < -55 db Polarization Dependent Loss < 0.06 db < 0.08 db Repeatability ±0.01 db ±0.02 db Crosstalk < -80 db < -70 db Input Power 300mW Switching Speed 65ms + 10ms / channel Wavelength Window 1480 to 1650 nm Durability > 10 million cycles Operating Temperature 0 to +50 C Storage Temperature - 40 to +70 C Humidity 95% RH non-condensing Operating Voltage 5.0 ± 0.25 VDC 6.0 VDC Maximum Output Channels 24 or 32 Housing Dimension (H W L) mm up to 1x mm up to 1x32 Housing Weight 470 g 500 g Power consumption 1.0 W 3.5 W Control Interface (All I/O pins are ESD protected) 16-pin TTL 26-pin TTL RS-232 Note: All specifications referenced without connectors All optical measurements taken after temperature has been stabilized at 23 ± 3 ºC All specifications applied for bi-directional transmission 1. Add 0.7 db for two connectors 2. Over the operating wavelength range. Add 0.3 db typical for variations over temperature. Rev 1.1_09/2003 Page 2 of 16

5 Interface Connectors The LT900 switch can be configured with one and only one of the following interface connectors: pin pin 3. RS pin connector A 16 pin, 0.1 spacing dual row connector serves as the interface to all the electrical connections to the LT900 switch. The connector is attached to the switch through a 16 wire ribbon cable. There are seven pins to indicate the channel address (D0-D6), two input control pins (STROBE, RESET), two output status pins (BUSY, ERROR), two digital power pins (D5V, DGND), and two analog power pins (A5V, AGND). All I/O pins are ESD protected pin connector A 26 pin, 0.1 spacing dual row connector serves as the interface to all the electrical connections to the LT900 switch. The connector is attached to the switch through a 26 wire ribbon cable. There are seven pins to indicate the channel address (D0-D6), two input control pins (STROBE, RESET), two output status pins (BUSY, ERROR), and six power pins (2 +5V, 4 GND). All I/O pins are ESD protected RS-232 connector A standard sub-d9 female connector serves as the interface to the I/O pins of the LT900 switch. Separate power and ground wires are provided and must be attached to a 5V source. The wires and the RS-232 connector are attached to the switch through a 16 wire ribbon cable. The RS-232 pins are ESD protected. +5V Power Ground RS-232 Rev 1.1_09/2003 Page 3 of 16

6 16 Pin Connector Assignment Pin No. Signal Type Definition 1 A5V Power Analog +5V 2 AGND Power Analog Ground 3 DGND Power Digital Ground 4 D5V Power Digital +5V 5 STROBE Input High to low pulse read channel address and reset pins High ignore state of channel address and reset pins 6 BUSY Output Low idle High switching 7 ERROR Output Low normal operation High internal error 8 RESET Input Low switch to off (reset) position High normal operation 9 D0 Input Channel address bit 0 (LSB) 10 D1 Input Channel address bit 1 11 D2 Input Channel address bit 2 12 D3 Input Channel address bit 3 13 D4 Input Channel address bit 4 14 D5 Input Channel address bit 5 15 D6 Input Channel address bit 6 (MSB) Reserved Note: All TTL inputs and outputs are pulled high to 5 VDC through 10K ohm resistors. Low = 0V, High = +5V Rev 1.1_09/2003 Page 4 of 16

7 26 Pin Connector Assignment Pin No. Signal Type Definition 1 GND Power Ground 2 GND Power Ground 3 BUSY Output Low idle High switching 4 DO Input Channel address bit 0 (LSB) 5 ERROR Output Low normal operation High internal error 6 D1 Input Channel address bit Not connected 8 D2 Input Channel address bit Not connected 10 D3 Input Channel address bit Not connected 12 D4 Input Channel address bit 4 13 STROBE Input High to low pulse read channel address and reset bits High ignore state of channel address and reset bits 14 D5 Input Channel address bit Not connected 16 D6 Input Channel address bit 6 (MSB) Not connected 18 RESET Input Low switch to off (reset) position High normal operation 19 GND Power Ground 20 GND Power Ground Not connected Reserved 23 5V Power +5 V power 24 5V Power +5 V power Not connected Not connected Note: All TTL inputs and outputs are pulled high to 5 VDC through 10K ohm resistors. Low = 0V, High = +5V Rev 1.1_09/2003 Page 5 of 16

8 RS232 Communication Parameters and Pin Assignments RS232 communication parameters Baud Rate 9600 Word Length 8 Stop Bits 1 Parity N Termination 0xD RS232 receptacle pin assignments are listed as follows: Pin No. Definitions 1 No connection 2 Transmit data 3 Receive data 4 Connect to Pin 6 5 Signal ground 6 Connect to Pin 4 7 CTS 8 RTS 9 No connection Rev 1.1_09/2003 Page 6 of 16

9 RS-232 Commands & Messages Command Format *IDN? MAX#? *RST SWITCH:0 SWITCH:n SWITCH? Example Description Command Response Note Instrument identification query Response: M Vx M: model name x: firmware version Maximum optical channels query. Response: n n: 1 ~ N Reset system command. Switches input to the off (reset) position and executes internal test. Response: 0,OK internal test passed ERR3 internal test fail Switches input to the off (reset) position Response: 00,OK Switches input to optical channel n Response: n,ok n: 00 ~ N ERR2 n > N Queries what optical channel number the LT900 switch is currently at Response: n n: 1 ~ N : ASCII character 13 (hex D) N: maximum # of optical channels *IDN? MAX#? LT900 V Model Name: LT900 Firmware Version: Maximum # of optical channels is 17 *RST 0,OK Internal test passed SWITCH:0 SWITCH:6 SWITCH? 00,OK 06,OK 12 Switch input to optical channel 6 Switch is currently at optical channel number 12 Error Message Description Cause ERR1 Command format not recognized Misspelled / unrecognized command ERR2 Switch channel beyond range Using the SWITCH:n command with an optical channel number n greater than the maximum number of optical channels for the switch ERR3 Internal error Misconnection, product failure : ASCII character 13 (hex D) Rev 1.1_09/2003 Page 7 of 16

10 Operating Instructions 16 and 26 Pin Connector Operating Instructions Initialization: 1. Attach the connector from the LT900 switch to an appropriate control circuit 2. Once power is applied, wait until the BUSY pin is LOW 3. Verify that the ERROR pin is LOW Note: The initial optical channel after power-up of the LT900 switch is the off (reset) position, optical channel 0. To change an optical channel: 1. If the BUSY pin is HIGH, wait until it is LOW 2. Set RESET HIGH 3. Load the CHANNEL ADDRESS bits with the data that corresponds to the optical channel number to switch to as provided in the Channel Address to Optical Channel Number Conversion Table 4. Pulse the STROBE pin To reset or turn off (optically) the switch: 1. If the BUSY pin is HIGH, wait until it is LOW 2. Set RESET LOW 3. Pulse the STROBE pin Channel Address to Optical Channel Number Conversion Table Optical CHANNEL ADDRESS RESET Channel # D0 D1 D2 D3 D4 D5 D6 0 (off) 0 x x x x x x x Note: refer to product specifications for maximum number of channels available for each product Rev 1.1_09/2003 Page 8 of 16

11 RS-232 Operating Instructions Initialization: 1. Use an RS-232 cable to connect the LT900 switch to an RS-232 port 2. Configure the serial port as follows: Baud Rate 9600 Word Length 8 Stop Bits 1 Parity N Termination : ASCII character 13 (hex D) Note: The initial optical channel after power-up of the LT900 switch is the off (reset) position, optical channel 0. To change an optical channel: 1. SWITCH:n where n is the optical channel number to switch to. 2. Read the response from the RS-232 port. If the command executed succesfully, the response will be n,ok where n is the optical channel number specified in (1). NOTE: If n is greater than the maximum optical channels for the switch the response will be ERR2. To reset or turn off (optically) the switch: 1. SWITCH:0 or *RST 2. Read the response from the RS-232 port. Successful command execution results in a response of 00,OK for the SWITCH:0 command and 0,OK for the *RST command. To verify switch position: Soft verification 1. SWITCH? 2. Read optical channel response from the RS-232 port. The data format will be n where n is the current optical channel number. Hard verification 1. Note current optical channel number 2. *RST 3. Verify response of 0,OK 4. SWITCH:n where n is the optical channel number in (1) 5. Verify response of n,ok 6. SWITCH? 7. Read optical channel response from the RS-232 port. The data format will be n where n is the current optical channel number. Rev 1.1_09/2003 Page 9 of 16

12 Micro-controller Interface The following diagrams outline the setup required to connect the LT900 switch to a microcontroller. The LT900 switch has 9 input bits and 2 output bits that the micro-controller must interface. The initial optical channel after power-up of the LT900 switch is the off (reset) position, optical channel 0. In this position, all optical outputs are dark. 16 pin Connector +5V +5V 9, 10, 11, 12, 13, 14, 15 5 LT900 Switch DO-D6 STROBE Analog 5V Digital 5V 1 4 Microcontroller 8 RESET Digital GND BUSY ERROR Analog GND 2 26 pin Connector +5V LT900 Switch 4, 6, 8, 10, 12, 14, 16 DO-D6 5V 23, STROBE Microcontroller 18 RESET 5 3 BUSY ERROR GND 1, 2, 19, 20 Rev 1.1_09/2003 Page 10 of 16

13 Pin Function Definition The following definitions are valid for the 16 pin and 26 pin connectors. CHANNEL ADDRESS (D0, D1, D2, D3, D4, D5, D6) CHANNEL ADDRESS consists of seven bits that represent the optical channel number. Refer to the product specifications for the maximum number of channels available for each product. Note that optical channel 1 is CHANNEL ADDRESS 0, as listed in the table below. The LT900 switches to the optical channel represented by CHANNEL ADDRESS on high to low transitions of the STROBE pin. A minimum hold time of 15 µs for the CHANNEL ADDRESS is required after the STROBE pin goes low. Channel Address to Optical Channel Number Conversion Table Optical RESET CHANNEL ADDRESS Channel # D0 D1 D2 D3 D4 D5 D6 0 (off) 0 x x x x x x x Note: refer to product specifications for maximum number of channels available for each product. STROBE The STROBE bit triggers the reading of the CHANNEL ADDRESS and RESET pins by the LT900 switch. A high to low transition of the STROBE bit latches the value of the CHANNEL ADDRESS and RESET pins into the LT900 switch. The minimum pulse width for the STROBE pin is 1 µs. The LT900 will switch to the channel represented by the CHANNEL ADDRESS and RESET bits immediately following the pulsing of the STROBE pin. Rev 1.1_09/2003 Page 11 of 16

14 RESET The RESET pin is used to switch the LT900 to the off (reset) position and execute a self-test. In normal operation the pin is set HIGH. Holding RESET low and pulsing the STROBE pin switches the LT900 to optical channel number 0, the reset position. The minimum holding time for the RESET pin is 15 µs after the STROBE pulse. BUSY The BUSY pin indicates the state of the LT900 switch. BUSY is LOW when the switch is idle. BUSY changes to HIGH 600ns max after STROBE goes LOW. BUSY remains HIGH until the switch reaches the requested channel. Do not attempt an operation when BUSY is HIGH, wait until the BUSY bit is LOW. ERROR The ERROR bit contains the result of the most recent self-test. When the LT900 switch is powered up and after a reset operation, the LT900 switch executes a self-test. If no problem is encountered during self-test, then ERROR will be set LOW. If the LT900 switch finds a problem during the self-test, then ERROR will be set HIGH. A HIGH value on the ERROR pin serves as a warning of a product fault. Rev 1.1_09/2003 Page 12 of 16

15 Timing Diagram The illustration below consists of two operations: (1) changing the optical channel and (2) a reset. (1) Changing the optical channel RESET is set high. The optical channel number is loaded in D0-D6. While BUSY is low, STROBE is pulsed low for a minimum of 1µs. The values for DO-D6 must be held for a minimum of 15 µs after STROBE is applied. BUSY goes high < 1 µs after STROBE goes low. Once the LT900 finishes switching to the optical channel specified in D0-D6, BUSY goes low. (2) Reset During a reset operation, the values of D0-D6 are ignored. While BUSY is low, RESET is brought low. STROBE is then pulsed low. RESET must be held low for a minimum of 15 µs after STROBE is applied. BUSY goes high < 1 µs after STROBE goes low. Once the LT900 finishes the reset operation, BUSY is set low. Changing the optical channel Reset DO-D6 Channel RESET Tch Tr STROBE Tstr Tsw Trst BUSY Symbol Definition Minimum Maximum LT917 Tstr Strobe pulse width 1 µs Tch Channel address hold time 15 µs Tsw Switching cycle time 300 ms Tr Reset pin hold time 15 µs Trst Reset cycle time 450 ms Rev 1.1_09/2003 Page 13 of 16

16 Testing Testing: Interface: 16 or 26 pin connector Standard 1xN switch controllers available from LIGHTech Fiberoptics can be connected to the LT900 switch for testing and evaluation purposes. The controller allows for both sequential and random switching and can be configured to have an RS-232 and/or GPIB interface. 1. Connect the 16 pin or 26 pin connector from the LT900 switch to the proper connector from the switch controller. 2. Turn on the power to the switch controller. 3. Use the front panel of the controller or its remote interface (RS232/GPIB) to directly control the LT900 switch. Refer to LIGHTech s 1xN switch controller operation manual for further details on how to operate the 1xN switch controller. Labview is a registered trademark of National Instruments Rev 1.1_09/2003 Page 14 of 16

17 Housing Drawing LT900 SERIES Rev 1.1_09/2003 Page 15 of 16

18 Rev 1.1_09/2003 Page 16 of 16