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Mega

Plus

®

 Model 1.4i 

3. CAMERA OPERATION 

3.1 Introduction 

 
The 

Mega

Plus Camera, Model 1.4i does not have any manual controls.  Camera operation is 

accomplished by commands sent to the camera through a serial data link from a personal 
computer.  In this chapter we will present the various operating modes of the camera with an 
explanation of the function followed by the command sequence that must be transmitted by the 
computer.  The control lines to the camera can be configured as an RS232 or an RS422 serial 
data link.  The camera is ordered from the factory configured one way or the other.  The 
command syntax is the same in either case. 
 

3.2  Serial Communications Protocol 

 
The camera uses a full duplex UART type asynchronous system, using standard nonreturn-to-
zero (NRZ) format (one start bit, eight data bits, one stop bit, no parity).  The baud rate is fixed at 
9600.  The character code is based on the ASCII standard. 
 
The character flow control protocol is XON/XOFF.  XON is assigned DC1 (control-Q) and XOFF 
is assigned DC3 (control-S).  The receiver sends the XOFF character when it wants the sender to 
pause in sending data and an XON character when it wants the sender to resume. 
 
The camera will recognize a command as three command characters, followed by a space bar 
character, followed by an argument that consists of one or more characters, ended by the 
carriage return and line feed characters.  The camera responds to a valid command with a 
carriage return and line feed (CR-LF). 
 
The camera will recognize a query as three command characters, followed by the question mark 
character, then ended by the carriage return character.  
 
The camera responds to a query with three command characters, followed by a space bar character, followed by an 
argument that consists of one or more characters, then ended by carriage return character and line feed (CR-LF). 

3.3 Error Messages 

The camera can respond to an erroneous command or query in one of three possible ways. 
 

MESSAGE FROM CAMERA 

EXPLANATION 

ERROR-SYNTAX 

The camera cannot make sense of the command. 

ERROR-ARGUMENT OUT OF RANGE 

The command is recognized, but the argument is 
out of range or indecipherable. 

ERROR-TRANSMISSION 

The receiver detected a transmission error such 
as buffer overflow, parity, noise, or framing 

 

3.4 Mode Control 

The 

Mega

Plus Camera operates in one of three modes, TRIGGER, CONTINUOUS, or 

CONTROL.  The mode of operation is selected by the mode command.  The mode command’s 
fourth option, PARALLEL INTERFACE, delegates mode selection to three control lines, MC0 - 
MC2, input through the Digital Interface Connector 
 
 
 
 

91000050-002 Revision A 

3-1 

USER’S MANUAL 

Содержание 1.4i

Страница 1: ... 1 2001 The MegaPlusâ Model 1 4i Camera User s Manual Redlake MASD Inc 11633 Sorrento Valley Road San Diego California 92121 1097 Telephone 800 854 7006 USA and Canada only Outside the USA 858 481 8182 Fax 858 481 6254 Internet www redlake com ...

Страница 2: ...the equipment and receiver Connect the equipment into an outlet on a circuit different from that to which the receiver is connected Consult the dealer or an experienced radio TV technician for help This equipment has been certified to comply with the limits for a Class A computing device pursuant to FCC rules In order to maintain compliance with FCC regulations shielded cables must be used with th...

Страница 3: ...mage to the sensor Any laser powerful enough to produce localized heating at the surface of the sensor will cause damage even if the camera power is off A sensor damaged by laser light is NOT covered by the warranty OPERATING TEMPERATURE The MegaPlus camera is designed to operate satisfactorily in an environment where the ambient temperature is between 0 and 35 C 32 and 95 F with no water condensa...

Страница 4: ...el Interface 3 2 3 5 Shutter 3 3 3 6 Exposure 3 4 3 7 Trigger 3 5 3 8 Gain 3 6 3 9 Black Level 3 6 3 10 Strobe Polarity 3 7 3 11 Defect Concealment 3 7 3 12 Reset 3 7 3 13 Save 3 8 3 14 Status Query 3 8 3 15 Identification Query 3 8 4 INTERFACE SPECIFICATIONS 4 1 4 1 Introduction 4 1 4 2 Digital Video Connector 4 1 4 3 Digital Video Outputs 4 1 4 4 Timing Outputs 4 1 4 5 Control Inputs 4 2 4 6 Mod...

Страница 5: ...Frame Grabber Cable 4 6 Figure 4 6 68 Pin Frame Grabber Connector 4 7 Figure 4 7 9 Pin PC COM Port 68 Pin Frame Grabber Cable 4 8 Figure 4 8 Sensor Organization 4 9 Figure 4 9 Exposure Timing Waveform 4 11 Figure 4 10 Frame Timing Continuous Mode Waveform 4 12 Figure 4 11 Line Timing Waveform 4 13 Figure 4 12 Pixel Clock Timing 4 13 LIST OF TABLES Table 4 1 Mode Control Lines 4 2 Table 4 2 Digital...

Страница 6: ...REDLAKE MASD INC THIS PAGE INTENTIONALLY LEFT BLANK 91000050 002 Revision A vi 10 01 01 ...

Страница 7: ...mera The benefit of having a 100 fill ratio is reduced aliasing improved subpixel accuracy and a 100 light sensitive area The Camera output has an 8 bit digital video output containing 256 levels of gray for each pixel Exposure is adjustable from 1 millisecond to 100 seconds in 1 millisecond increments using the internal exposure control Exposure times from 1 millisecond to the longest time practi...

Страница 8: ...amera Chapter 3 is intended to give the user some insight into how to choose the correct mode of operation for this MegaPlus camera The correct mode of operation is defined as what will get the imaging results you are looking for Chapter 4 details the specifications of the MegaPlus camera with the intent to give you all of the information you require when using this camera 91000050 002 Revision A ...

Страница 9: ...damage misuse or abuse The Camera having been repaired or tampered with by persons other than Redlake personnel customer personnel trained by Redlake or without permission of Redlake Shipping damage is not covered by this warranty The purchaser has the responsibility to place a claim of damage in shipment with the carrier REDLAKE MASD INC MAKES NO OTHER WARRANTIES EXPRESSED IMPLIED OR OF MERCHANTA...

Страница 10: ...REDLAKE MASD INC THIS PAGE INTENTIONALLY LEFT BLANK 91000050 002 Revision A 1 4 10 01 01 ...

Страница 11: ...ens to the camera Figure 2 1 Camera Body 2 1 2 Attaching the Lens The camera can be purchased with either a C mount or F mount lens adapter If your camera is equipped with an F mount lens adapter insert the lens into the locking ring then rotate the lens counterclockwise until it clicks into position To remove the lens hold the release button down as you rotate the lens clockwise If your camera is...

Страница 12: ...ut signal can be used to fire a strobe light This output signal is TTL compatible and can drive a 50 ohm load A strobe light with a flash duration of less than 1 millisecond is useful for capturing images of fast moving objects 2 2 3 DC Power Input This two pin connector is the power input for the camera The power supply voltage should be between 12 and 28 volts DC measured at the connector on the...

Страница 13: ...Model 1 4i 2 3 Cables There are three different cables available to connect the MegaPlus Camera to your computer as shown in Figure 2 4 below Figure 2 4 1 4i Cable Types 91000050 002 Revision A 2 3 USER S MANUAL ...

Страница 14: ...ns supplied by the frame grabber manufacturer when you are using their cables to install your camera If using Redlake supplied cables connect the camera as shown in Figure 2 5 below Figure 2 5 Component Connection Diagram 91000050 002 Revision A 2 4 10 01 01 ...

Страница 15: ... ordered originally a piece of clear glass will be installed in place of the filter The filter or its glass replacement keep the interior of the camera sealed from dust and should never be removed in other than a clean room environment Because of the high resolution of the camera a single speck of dust on the sensor is very noticeable If you need to use different filters in your application from t...

Страница 16: ...REDLAKE MASD INC THIS PAGE INTENTIONALLY LEFT BLANK 91000050 002 Revision A 2 6 10 01 01 ...

Страница 17: ...l recognize a command as three command characters followed by a space bar character followed by an argument that consists of one or more characters ended by the carriage return and line feed characters The camera responds to a valid command with a carriage return and line feed CR LF The camera will recognize a query as three command characters followed by the question mark character then ended by ...

Страница 18: ...ed allows The exposure command sets the exposure time and indirectly the frame rate Each new exposure starts as soon as the previous image has been transferred to the camera output by the camera electronics 3 4 3 Control The start and exposure time of each picture is controlled directly by the user Control is accomplished by the EXPOSE input pins in the Digital Interface connector on the rear pane...

Страница 19: ...turned off with the blades open if you are working in a darkened area with a light source that is flashed The camera is always gathering light even as an image is being read from the sensor If there is light on the subject between exposures the shutter should be used to prevent image smear If you need to acquire a dark current frame turn the shutter off with the blades closed and transfer a frame ...

Страница 20: ...e When your application involves low light levels and a subject that is not moving exposure times of more than one second may be necessary As you push the exposure time beyond one second you may notice that image quality deteriorates This is caused by sensor dark current accumulating over time The CONTROL mode allows you to extend the exposure time beyond 100 seconds but you should understand that...

Страница 21: ...back on TRM Queries the current EXPOSE polarity TRM P TRM N TRM O Means EXPOSE signal is set to positive logic Means EXPOSE signal is set to negative logic Means EXPOSE input port has been disabled This can only occur if TRE 0 or 1 has been executed TRE Queries the current state of the TRIGGER command TRE 0 TRE 1 Means an exposure is taking place Means the camera is in the Transfer Frame and then ...

Страница 22: ...lack level control functions much like the brightness control on a television set To get reasonable results under most circumstances use the BKF or fixed black level The fixed video black level is set at the factory so that the output video is just above the black clipping level with the lens capped The black level can be varied over a range of plus or minus 50 percent of peak white video This adj...

Страница 23: ...r use with the MegaPlus 1 4i camera 3 11 Defect Concealment Occasionally sensors are not perfect and have some areas that react differently to light These problem pixels are usually seen as a column that is different in intensity than the immediately adjacent area It is possible to characterize a sensor identifying the defective columns and then program their locations into the camera at the facto...

Страница 24: ...and TYPE IN RESPONSE EXPLANATION STS DEF xx GAE xxx BKE xxxx MDE xx SHE xx EXE xx TRM x TRE x STP x Gives complete camera status with one query The following parameters are transmitted with a carriage return after each parameter Shows Defect Concealment status Shows Gain setting Shows Black Level setting Shows the operating Mode Shows the Shutter status Shows the Exposure time Shows the Trigger lo...

Страница 25: ...es long We have taken precautions to prevent damage to the CCU should a SCSI device accidentally be connected to this port 4 3 Digital Video Outputs The digital video output of the camera has eight bits labeled MSB through MSB 7 These signals are output as differential pairs with signal levels conforming to the RS422 specification The noninverting part of the differential pair is present on output...

Страница 26: ...MC2 provide backward compatibility with earlier MegaPlus Camera control signals Each of these inputs is designed to accept TTL level signals referenced to ground at the connector MC0 and MC1 set the operating mode and MC2 enables the shutter The truth table for the control lines is as follows Table 4 1 Mode Control Lines MC2 Pin 33 TTL Input MC1 Pin 32 TTL Input MC0 Pin 31 TTL Input Shutter Operat...

Страница 27: ...sed 48 Not Used 15 Not Used 49 Not Used 16 Not Used 50 Not Used 17 Not Used 51 Not Used 18 Not Used 52 Not Used 19 Not Used 53 Not Used 20 Not Used 54 Not Used 21 Not Used 55 Not Used 22 SER CNTRL OUT 56 SER CNTRL OUT Camera 23 SER CNTRL IN 57 SER CNTRL IN User 24 Not Used 58 Not Used 25 FRME ENA 59 FRME ENA Camera 26 LINE ENA 60 LINE ENA Camera 27 Not Used 61 Not Used 28 Not Used 62 Not Used 29 P...

Страница 28: ...REDLAKE MASD INC Refer to Table 4 2 for Pinout Figure 4 2 68 Pin Digital Interface Cable 91000050 002 Revision A 4 4 10 01 01 ...

Страница 29: ...4 Camera 13 MSB 5 32 MSB 5 Camera 14 MSB 6 33 MSB 6 Camera 15 MSB 7 34 MSB 7 Camera 16 GROUND 35 GROUND Camera 17 EXPOSE 36 Not Used User 18 MC0 37 MC1 User 19 MC2 37 Pin female D subminiature connector as viewed at the end of the cable Figure 4 3 37 Pin Connector Table 4 4 9 Pin PC COM Port Cable Pinout PIN SIGNAL NAME PIN SIGNAL NAME 1 Open 6 Open 2 Camera TX from Camera 7 Connected to Pin 8 3 C...

Страница 30: ...REDLAKE MASD INC Refer to Tables 4 3 and 4 4 for Pinouts Figure 4 5 9 Pin PC COM Port 37 Pin Frame Grabber Cable 91000050 002 Revision A 4 6 10 01 01 ...

Страница 31: ...t Used 49 Not Used 16 Not Used 50 Not Used 17 Not Used 51 Not Used 18 Not Used 52 Not Used 19 Not Used 53 Not Used 20 Not Used 54 Not Used 21 Not Used 55 Not Used N C SER CNTRL OUT 56 SER CNTRL OUT Do Not Use N C SER CNTRL IN 57 SER CNTRL IN Do Not Use 24 Not Used 58 Not Used 25 FRME ENA 59 FRME ENA Camera 26 LINE ENA 60 LINE ENA Camera 27 Not Used 61 Not Used 28 Not Used 62 Not Used 29 PIX DATA S...

Страница 32: ...REDLAKE MASD INC Refer to Table for Pinout Figure 4 7 9 Pin PC COM Port 68 Pin Frame Grabber Cable 91000050 002 Revision A 4 8 10 01 01 ...

Страница 33: ...317H x 1 035V Elements Transferred Per Line 1 394 pixel clock pulses in each line transfer 1 317 for active video 77 for sync and blanking Lines Transferred Per Frame 1 037 one dark line at both bottom and top Pixel Size 6 8 x 6 8 microns square format Center to Center Pixel Spacing 6 8 microns vertical and horizontal unity fill ratio Active Area 8 98mm H x 7 04mm V photosensitive area 100 fill fa...

Страница 34: ...ate depends on both the frame transfer time and the exposure time 1 Frame Rate Exposure time frame transfer time 1 idle line time shutter transit time For exposures that are much shorter than the frame transfer time and when the shutter is off the frame transfer time dominates the above equation and the frame rate approaches the maximum 1 145 milliseconds 6 9 frames per second For an exposure time...

Страница 35: ...s means that the camera will not respond to the start or stop command until another line has been processed All exposure events are quantized in steps of one line time or 139 4 µsec This normally has no effect on exposure because one or two line times 0 1 to 2 ms is a small percentage of the total 10 to 500 millisecond exposure time NOTE Any asynchronous input pulse must be wide enough to be seen ...

Страница 36: ...the pixel that belongs in the upper left hand corner of the video display Each row of video data is output from left to right and the rows are presented from top to bottom The last pixel of the frame is placed in the lower right hand corner of the video display The video is transferred by shifting each row up one row The top row is shifted into a register that performs the parallel to serial conve...

Страница 37: ...gister When LINE ENABLE is high the information in that horizontal shift register is clocked serially to the camera s output circuits Image data is valid only when both FRAME ENABLE and LINE ENABLE are high the rest of the time the data are meaningless Figure 4 11 Line Timing Waveform 4 9 4 Pixel Timing PIXEL DATA STROBE is a 10 MHz square wave that runs continuously This clock drives the circuitr...

Страница 38: ...re time 15 millisecond shutter transition time 4 10 2 Camera Mechanical Housing All aluminum gasket sealed case Dimensions F mount C Mount 4 45 H x 3 90 W x 5 84 L 113 0 x 304 8 x 148 3mm 4 45 H x 3 90 W x 4 68 L 113 0 x 304 8 x 118 8mm Lens C Mount or F Mount Weight Approximately 3 pounds 1 26 Kg Mount Four 20 threaded holes 2 on top 2 on bottom Vibration 3G sinusoidal from 5 to 150 Hz Shock 20G ...

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