Abstract:
A master computer of a controlled system is interrelated with the executory computer of a peripheral device via a standard serial interface. This relationship centers in the programming of the executory computer to make available on command from the master computer substantially all of the functions of the peripheral device, as well as the data stored in the executory computer, and also to lock out the keyboard of the peripheral device on command to prevent operator intrusion.

Description:
BACKGROUND OF THE INVENTION 
     The functioning of computers is continually defining new relationships between personnel and equipment, and between equipment components. The term &#34;computer&#34; has come to include a device capable of both computation and the storage and retrieval of data. Integrated systems of computers have been developed in which a central computer is provided with the functions of other computers, which are commonly referred to as peripheral devices. This is the area of concern of the present invention. Master and peripheral computers are associated with an interface system through which the devices are able to communicate with each other. These systems have become standardized, so that the computers of different manufacturers may be interrelated without extensive modification. 
     New fields of utility are emerging rapidly with the explosive development of the computers and their functions. A typical example is the area in which the present invention has been initially developed. This is the association of computer-controlled densitometers with the highly-automated equipment used in the processing of photographic film and prints. The many functions of the processing installation are controlled by a master computer which regulates some of its own processing variables as a function of a data received from the densitometer. The densitometer is primarily a device for detecting the density of the various colors present in a sample being processed. The detection may be based upon the transmission of light through the sample, or reflected from its surface. These units have a number of applications, and are stock items that have been marketed in some quanity. Typically, the densitometer and the control master computer of the photographic processing system have been interrelated either through the activity of a human operator, or through a semi-automated arrangement in which the operator selects certain densitometer functions which are then dumped into the master computer via the interface system when called for. The presence of the human operator obviously presents the possibility of error, as well as injecting the time factor associated with human response. The master controller must also allocate communication time and hardware to the task of prompting the operator to establish the desired densitometer parameters such as color bandwidth, function, null values, and also advice the operator of errors such as values that may be out of range. It is obvious that a fully-automated system that would eliminate the presence of the operator would be highly desireable, but the accomplishment of this has had to await the present invention, which centers in a programming of the executory computer of the densitometer which is compatible with the standard RS-232 interface system. 
     SUMMARY OF THE INVENTION 
     The master computer controlling a system for processing photographic film and printing is interrelated with a densitometer via a standard serial interface associating the master computer with the executory computer of the densitometer. This is done by a special programming of the executory computer, and utilizes the full potential of a standard serial interface, a portion of which has been heretofore unused in conventional densitometer-processing relationships. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     The drawing presents a schematic block diagram showing the relationship of the functional sections of the densitometer and the interface system with the master computer controlling the processing installation. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawing, the area enclosed in dotted lines represents schematically the components of a standard densitometer, such as the X-RITE Model 310. Under normal operation, the executory computer 10 of this unit establishes the following primary functions: 
     1. Selecting the color bandwidths asked for by key entry at the key pad 11. 
     2. Selecting the density function asked for by key entry. 
     3. Controlling the analog to digital convertor 12 that converts the analog data from the optical sensor 13 to digital information to be processed by the executory computer 10. The optical sensor system is responsive to light projected through the film sample 14 from the lamp 15 energized by the lamp driver 16. 
     4. Computing data for the density function selected. 
     5. Updating display memory with correct density or time data. 
     6. Initiating and controlling transmission of data via the serial interface system 17. 
     A secondary function is also established by the executory computer during intervals established by a timer-generated real-time interrupt two hundred to three hundred microseconds in duration, occurring approximately two times per millisecond. During the execution of this function, the data shown on the display 18 is updated. This data and the key status information are also stored in the executory computers RAM memory. 
     The association of the denistometer with the master computer 19 (such as the Kodak Technet, Trademarks of the Eastman Kodak Company) is established by the serial interface 17, which may be a standard RS-232 device. Control of the densitometer by the master computer takes place when it transmits to the densitometer via the serial interface a command string in the form of serial signals. Upon receiving the first character of the command string, the serial interface 17 issues an interrupt to the executory computer that causes the execution of the primary functioning of the computer to be suspended and replaced with a monitor program that accepts the command string signals. These instructions may call for any of the following actions: 
     1. The executory computer is instructed to write to its RAM memory at the address specified, the data which may also be included in the command string. 
     2. The executory computer is to read from its RAM memory the data at the address specified, and transmit it to the master computer via the serial interface. 
     3. The executory computer may be instructed to set the switches controlling special functions such as blanking of displays, locking the keyboard, choice of filter banks, and so forth. 
     4. An instruction to the executory computer to go back to normal primary functions. 
     The monitor program continues to accept data through the serial interface until it receives a delimiter character at the end of the command string, at which time it performs a specific action called for by that command string. 
     In this relationship between the master computer and the executory densitometer computer, the master unit can at all times &#34;know&#34; the current function and color bandwidths selected at the densitometer. The controlling system can also select densitometer functions, color bandwidths, null values, and operating parameters independent of operator interaction. These highly important functions are obtainable with a mininal cost because the transmission of command strings to the densitometer is done via the unused half of the bi-directional RS-232 port already present to receive density data from the densitometer for ordinary manual operation. 
     These remote control functions are established by appropriately programming the executory computer of the densitometer, this computer being of the type represented by the model MCS-51 manufacturered by Intel. In the program that will be set-out below in standard form, the first column represents the machine address of the instructions, the second column the instructions in machine language, and the next (double) column gives the line numbers of the program. The last three columns (to the right) present the labels, instructions, and operands in source code. 
     
         __________________________________________________________________________MCS-51 MACRO ASSEMBLER X338.34E 11:12LOC OBJ     LINE SOURCE__________________________________________________________________________       2894 +1            $IC(PANDP.SRC)098C     =1 2895 PUSH --NIBBLE --R2                        EQU  DSPLY --IT    =1 28960EEC    CODO =1 2897 BEGIN --P --AND --P:                        PUSH PSW0EEE    C0E0 =1 2898             PUSH ACC0EF0    75D010    =1 2899             MOV  PSW,#10H ;SET REG    =1 29000EF3    3098FD    =1 2901 WAIT --FOR --BYTE:                        JNB  RI,$0EF6    C298 =1 2902             CLR  RI    =1 29030EF8    AC99 =1 2904 INPUT --BYTE:                        MOV  R4,SBUF0EFA    53147F    =1 2905             ANL  RB2 --R4,#7FH0EFD    BC0A7D    =1 2906             CJNE R4,#0AH,PUSH --COMMAND --DATA    =1 29070F00    B43106    =1 2908 TAKE --ACTION:                        CJNE A,#`1` AND 7FH,SKIP --10F03    CA   =1 2909             XCH  A,R20F04    C4   =1 2910             SWAP A0F05    13   =1 2911             RRC  A0F06    92B4 =1 2912             MOV  T0,C0F08    CA   =1 2913             XCH  A,R2    =1 29140F09    B43206    =1 2915 SKIP --1:   CJNE A,#`2` AND 7FH,SKIP --20F0C    CA   =1 2916             XCH  A,R20F0D    C4   =1 2917             SWAP A0F0E    13   =1 2918             RRC  A0F0F    921B =1 2919             MOV  NO --KEYS --BIT,C0F11    CA   =1 2920             XCH  A,R2    =1 29210F12    B43306    =1 2922 SKIP --2:   CJNE A,#`3` AND 7FH,SKIP --30F15    CA   =1 2923             XCH  A,R20F16    C4   =1 2924             SWAP A0F17    13   =1 2925             RRC  A0F18    921A =1 2926             MOV  NO --DSP --BIT,C0F1A    CA   =1 2927             XCH  A,R2    =1 29280F1B    B43407    =1 2929 SKIP --3:   CJNE A,#`4` AND 7FH,SKIP --40F1E    CA   =1 2930             XCH  A,R20F1F    C4   =1 2931             SWAP A0F20    13   =1 2932             RRC  A0F21    B3   =1 2933             CPL  C0F22    9219 =1 2934             MOV  P --A --C,C0F24    CA   =1 2935             XCH  A,R2    =1 29360F25    A912 =1 2937 SKIP --4:   MOV  R1,RB2 --R20F27    B45204    =1 2938             CJNE A,#`R` AND 7FH,SKIP --R0F2A    E7   =1 2939             MOV  A,@R10F2B    F190 =1 2940             ACALL                             OUTPUT0F2D    E4   =1 2941             CLR  A    =1 29420F2E    B45702    =1 2943 SKIP --R:   CJNE A,#`W` AND 7FH,SKIP --W0F31    A713 =1 2944             MOV  @R1,RB2 --R3    =1 29450F33    B45502    =1 2946 SKIP --W    CJNE A,#`U` AND 7FH,$+50F36    8003 =1 2947             SJMP $+50F38    B44C1E    =1 2948             CJNE A,#`L` AND 7FH,SKIP --U0F3B    CB   =1 2949             XCH  A,R30F3C    C083 =1 2950 CM --R:     PUSH DPH0F3E    C082 =1 2951             PUSH DPL0F40    8A82 =1 2952             MOV  DPL,R20F42    8B83 =1 2953             MOV  DPH,R30F44    BB0200    =1 2954             CJNE R3,#02,$+30F47    5007 =1 2955             JNC  CM --W0F49    12072F    =1 2956             CALL RAM --READ0F4C    F190 =1 2957             ACALL                             OUTPUT0F4E    8003 =1 2958             SJMP CM --EXIT0F50    120767    =1 2959 CM --W:     CALL RAM --WRITE0F53    D082 =1 2960 CM --EXIT:  POP  DPL0F55    D083 =1 2961             POP  DPH0F57    809A =1 2962             JMP  WAIT --FOR --BYTE    =1 29630F59    B44902    =1 2964 SKIP --UL:  CJNE A,#`I` AND 7FH,SKIP --0F5C    80DE =1 2965             SJMP CM --R    =1 29660F5E    B45310    =1 2967 SKIP --I:   CJNE A,#`S` AND 7FH,GO --?0F61    CA   =1 2968             XCH  A,R20F62    C0A0 =1 2969             PUSH P20F64    5403 =1 2970             ANL  A,#030F66    23   =1 2971             RL   A0F67    23   =1 2972             RL   A0F68    23   =1 2973             RL   A0F69    F5A0 =1 2974             MOV  P2,A0F6B    12006D    =1 2975             CALL WRITE --PULSE0F62    D0A0 =1 2976             POP  P20F70    CA   =1 2977             XCH  A,R2    =1 29780F71    B44707    =1 2979 GO --?:     CJNE A,#`G` AND 7FH,WFB0F74    D0E0 =1 2980             POP  ACC0F76    DODO =1 2981             POP  PSW0F78    D2AC =1 2982             SETB ES0F7A    22   =1 2983             RET    =1 29840F7B    C1F3 =1 2985 WFB:        JMP  WAIT --FOR --BYTE    =1 2986    =1 2987 PUSH --COMMAND --DATA:0F7D    BC0D02    =1 2988             CJNE R4,#0DH,$+50F80    E100 =1 2989             JMP  TAKE --ACTION0F82    B43A00    =1 2990             CJNE A,#3AH,$+30F85    4002 =1 2991             JC   $+40F87    24F9 =1 2992             ADD  A,#-70F89    540F =1 2993             ANL  A,#0FH0F8B    318C =1 2994             CALL PUSH --NIBBLE --R20F8D    EC   =1 2995             MOV  A,R4    =1 2996 ;           CALL PRINT --ACC0F8E    C1F3 =1 2997             JMP  WAIT --FOR --BYTE    =1 29980F90    FD   =1 2999 OUTPUT:     MOV  R5,A0F91    C4   =1 3000             SWAP A0F92    517B =1 3001             CALL PRINT --ACC-20F94    ED   =1 3002             MOV  A,R50F95    517B =1 3003 CONV --AND --PR:                        CALL PRINT --ACC-20F97    4180 =1 3004             JMP  PR --CR --LF       3005 END__________________________________________________________________________ 
    
     It is very desireable to provide the master computer with the capability to lock out the keyboard, and blank the displays of the densitometer to prevent operator intrusion and distraction when the action of the operator is not appropriate. This can be accomplished by the addition of the following program lines preceding the program printed above: 
     
         __________________________________________________________________________09A4 201B37     =2 2890            JB NO --KEYS --BIT, SKIP --KEY09DE 09   =2 2891            SKIP --KEY: INC KEYDATA --PTR            &#34;KEYDATA --PTR&#34; AND THEN INC SAME0A49 301A01     =1 2892            JNB NO --DSP --BIT, $+40A4C E4   =1 2893            CLR A__________________________________________________________________________