Ladder Logic (lad) for S7-300 and S7-400 Programming
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1.18 Immediate Write Description For the Immediate Write function, a network of symbols must be created as shown in the example below. For time-critical applications, the current state of a digital output may have to be sent to an output module faster than the normal case of once at the end of the OB1 scan cycle. An Immediate Write writes to a digital output to a input module at the time the Immediate Write rung is scanned. Otherwise, you must wait for the end of the next OB1 scan cycle when the Q memory area is updated with the P memory state. To perform an immediate write of an output (or outputs) to an output module, use the peripheral output (PQ) memory area instead of the output (Q) memory area. The peripheral output memory area can be read as a byte, a word, or a double word. Therefore, a single digital output cannot be updated via a coil element. To write the state of a digital output to an output module immediately, a byte, word, or double word of Q memory that contains the relevant bit is conditionally copied to the corresponding PQ memory (direct output module addresses). ! Caution • Since the entire byte of Q memory is written to an output module, all outputs bits in that byte are updated when the immediate output is performed. • If an output bit has intermediate states (1/0) occurring throughout the program that should not be sent to the output module, Immediate Writes could cause dangerous conditions (transient pulses at outputs) to occur. • As a general design rule, an external output module should only be referenced once in a program as a coil. If you follow this design rule, most potential problems with immediate outputs can be avoided. Example Ladder network equivalent of Immediate Write to peripheral digital output module 5, channel 1. The bit states of the addressed output Q byte (QB5) are either modified or left unchanged. Q5.1 is assigned the signal state of I0.1 in network 1. QB5 is copied to the corresponding direct peripheral output memory area (PQB5). The word PIW1 contains the immediate status of I1.1. PIW1 is ANDed with W#16#0002. The result is not equal to zero if I1.1 (second bit) in PB1 is true ("1"). The contact A<>0 passes voltage if the result of the WAND_W instruction is not equal to zero. I 0.1 Q 5.1 Network 1 MOVE IN ENO EN OUT QB5 PQB5 Network 2 Bit Logic Instructions 1.18 Immediate Write Ladder Logic (LAD) for S7-300 and S7-400 Programming Reference Manual, 04/2017, A5E41524738-AA 31 In this example Q5.1 is the desired immediate output bit. The byte PQB5 contains the immediate output status of the bit Q5.1. The other 7 bits in PQB5 are also updated by the MOVE (copy) instruction. Bit Logic Instructions 1.18 Immediate Write Ladder Logic (LAD) for S7-300 and S7-400 Programming 32 Reference Manual, 04/2017, A5E41524738-AA Ladder Logic (LAD) for S7-300 and S7-400 Programming Reference Manual, 04/2017, A5E41524738-AA 33 2 Comparison Instructions 2.1 Overview of Comparison Instructions Description IN1 and IN2 are compared according to the type of comparison you choose: == IN1 is equal to IN2 <> IN1 is not equal to IN2 > IN1 is greater than IN2 < IN1 is less than IN2 >= IN1 is greater than or equal to IN2 <= IN1 is less than or equal to IN2 If the comparison is true, the RLO of the function is "1". It is linked to the RLO of a rung network by AND if the compare element is used in series, or by OR if the box is used in parallel. The following comparison instructions are available: • CMP ? I Compare Integer • CMP ? D Compare Double Integer • CMP ? R Compare Real Comparison Instructions 2.2 CMP ? I Compare Integer Ladder Logic (LAD) for S7-300 and S7-400 Programming 34 Reference Manual, 04/2017, A5E41524738-AA 2.2 CMP ? I Compare Integer Symbols CMP == I IN2 IN1 CMP <> I IN2 IN1 CMP < I IN2 IN1 CMP > I IN2 IN1 CMP <= I IN2 IN1 CMP >= I IN2 IN1 Parameter Data Type Memory Area Description box input BOOL I, Q, M, L, D Result of the previous logic operation box output BOOL I, Q, M, L, D Result of the comparison, is only processed further if the RLO at the box input = 1 IN1 INT I, Q, M, L, D or constant First value to compare IN2 INT I, Q, M, L, D or constant Second value to compare Description CMP ? I (Compare Integer) can be used like a normal contact. It can be located at any position where a normal contact could be placed. IN1 and IN2 are compared according to the type of comparison you choose. If the comparison is true, the RLO of the function is "1". It is linked to the RLO of the whole rung by AND if the box is used in series, or by OR if the box is used in parallel. Status word BR CC 1 CC 0 OV OS OR STA RLO /FC writes: x x x 0 - 0 x x 1 Example CMP >= I IN2 IN1 MW2 MW0 I 0.1 S Q 4.0 I 0.0 Output Q4.0 is set if the following conditions exist: • There is a signal state of "1" at inputs I0.0 and at I0.1 • AND MW0 >= MW2 Comparison Instructions 2.3 CMP ? D Compare Double Integer Ladder Logic (LAD) for S7-300 and S7-400 Programming Reference Manual, 04/2017, A5E41524738-AA 35 2.3 CMP ? D Compare Double Integer Symbols CMP == D IN2 IN1 CMP <> D IN2 IN1 CMP < D IN2 IN1 CMP > D IN2 IN1 CMP <= D IN2 IN1 CMP >= D IN2 IN1 Parameter Data Type Memory Area Description box input BOOL I, Q, M, L, D Result of the previous logic operation box output BOOL I, Q, M, L, D Result of the comparison, is only processed further if the RLO at the box input = 1 IN1 DINT I, Q, M, L, D or constant First value to compare IN2 DINT I, Q, M, L, D or constant Second value to compare Description CMP ? D (Compare Double Integer) can be used like a normal contact. It can be located at any position where a normal contact could be placed. IN1 and IN2 are compared according to the type of comparison you choose. If the comparison is true, the RLO of the function is "1". It is linked to the RLO of a rung network by AND if the compare element is used in series, or by OR if the box is used in parallel. Status word BR CC 1 CC 0 OV OS OR STA RLO /FC writes: x x x 0 - 0 x x 1 Comparison Instructions 2.3 CMP ? D Compare Double Integer Ladder Logic (LAD) for S7-300 and S7-400 Programming 36 Reference Manual, 04/2017, A5E41524738-AA Example CMP >= D IN2 IN1 MD4 MD0 I 0.1 S Q 4.0 I 0.0 I 0.2 Output Q4.0 is set if the following conditions exist: • There is a signal state of "1" at inputs I0.0 and at I0.1 • And MD0 >= MD4 • And there is a signal state of"1" at input I0.2 Comparison Instructions 2.4 CMP ? R Compare Real Ladder Logic (LAD) for S7-300 and S7-400 Programming Reference Manual, 04/2017, A5E41524738-AA 37 2.4 CMP ? R Compare Real Symbols CMP == R IN2 IN1 CMP <> R IN2 IN1 CMP < R IN2 IN1 CMP > R IN2 IN1 CMP <= R IN2 IN1 CMP >= R IN2 IN1 Parameter Data Type Memory Area Description box input BOOL I, Q, M, L, D Result of the previous logic operation box output BOOL I, Q, M, L, D Result of the comparison, is only processed further if the RLO at the box input = 1 IN1 REAL I, Q, M, L, D or constant First value to compare IN2 REAL I, Q, M, L, D or constant Second value to compare Description CMP ? R (Compare Real) can be used like a normal contact. It can be located at any position where a normal contact could be placed. IN1 and IN2 are compared according to the type of comparison you choose. If the comparison is true, the RLO of the function is "1". It is linked to the RLO of the whole rung by AND if the box is used in series, or by OR if the box is used in parallel. Status word BR CC 1 CC 0 OV OS OR STA RLO /FC writes: x x x x x 0 x x 1 Comparison Instructions 2.4 CMP ? R Compare Real Ladder Logic (LAD) for S7-300 and S7-400 Programming 38 Reference Manual, 04/2017, A5E41524738-AA Example CMP >= R IN2 IN1 MD4 MD0 I 0.1 S Q 4.0 I 0.0 I 0.2 Output Q4.0 is set if the following conditions exist: • There is a signal state of "1" at inputs I0.0 and at I0.1 • And MD0 >= MD4 • And there is a signal state of"1" at input I0.2 Ladder Logic (LAD) for S7-300 and S7-400 Programming Reference Manual, 04/2017, A5E41524738-AA 39 3 Conversion Instructions 3.1 Overview of Conversion Instructions Description The conversion instructions read the contents of the parameters IN and convert these or change the sign. The result can be queried at the parameter OUT. The following conversion instructions are available: • BCD_I BCD to Integer • I_BCD Integer to BCD • BCD_DI BCD to Double Integer • I_DINT Integer to Double Integer • DI_BCD Double Integer to BCD • DI_REAL Double Integer to Floating-Point • INV_I Ones Complement Integer • INV_DI Ones Complement Double Integer • NEG_I Twos Complement Integer • NEG_DI Twos Complement Double Integer • NEG_R Negate Floating-Point Number • ROUND Round to Double Integer • TRUNC Truncate Double Integer Part • CEIL Ceiling • FLOOR Floor Conversion Instructions 3.2 BCD_I BCD to Integer Ladder Logic (LAD) for S7-300 and S7-400 Programming 40 Reference Manual, 04/2017, A5E41524738-AA 3.2 BCD_I BCD to Integer Symbol BCD_I ENO EN IN OUT Parameter Data Type Memory Area Description EN BOOL I, Q, M, L, D Enable input ENO BOOL I, Q, M, L, D Enable output IN WORD I, Q, M, L, D BCD number OUT INT I, Q, M, L, D Integer value of BCD number Description BCD_I (Convert BCD to Integer) reads the contents of the IN parameter as a three-digit, BCD coded number (+/- 999) and converts it to an integer value (16-bit). The integer result is output by the parameter OUT. ENO always has the same signal state as EN. Status word BR CC 1 CC 0 OV OS OR STA RLO /FC writes: 1 - - - - 0 1 1 1 Example Q 4.0 I 0.0 MW10 BCD_I ENO EN IN OUT MW12 NOT If input I0.0 is "1" , then the content of MW10 is read as a three-digit BCD coded number and converted to an integer. The result is stored in MW12. The output Q4.0 is "1" if the conversion is not executed (ENO = EN = 0). Conversion Instructions 3.3 I_BCD Integer to BCD Ladder Logic (LAD) for S7-300 and S7-400 Programming Reference Manual, 04/2017, A5E41524738-AA 41 3.3 I_BCD Integer to BCD Symbol I_BCD ENO EN IN OUT Parameter Data Type Memory Area Description EN BOOL I, Q, M, L, D Enable input ENO BOOL I, Q, M, L, D Enable output IN INT I, Q, M, L, D Integer number OUT WORD I, Q, M, L, D BCD value of integer number Description I_BCD (Convert Integer to BCD) reads the content of the IN parameter as an integer value (16-bit) and converts it to a three-digit BCD coded number (+/- 999). The result is output by the parameter OUT. If an overflow occurred, ENO will be "0". Status word BR CC 1 CC 0 OV OS OR STA RLO /FC writes: x - - x x 0 x x 1 Example Q 4.0 I 0.0 MW10 I_BCD ENO EN IN OUT MW12 NOT If I0.0 is "1", then the content of MW10 is read as an integer and converted to a three-digit BCD coded number. The result is stored in MW12. The output Q4.0 is "1" if there was an overflow, or the instruction was not executed (I0.0 = 0). Conversion Instructions 3.4 I_DINT Integer to Double Integer Ladder Logic (LAD) for S7-300 and S7-400 Programming 42 Reference Manual, 04/2017, A5E41524738-AA 3.4 I_DINT Integer to Double Integer Symbol I_DINT ENO EN IN OUT Parameter Data Type Memory Area Description EN BOOL I, Q, M, L, D Enable input ENO BOOL I, Q, M, L, D Enable output IN INT I, Q, M, L, D Integer value to convert OUT DINT I, Q, M, L, D Double integer result Description I_DINT (Convert Integer to Double Integer) reads the content of the IN parameter as an integer (16-bit) and converts it to a double integer (32-bit). The result is output by the parameter OUT. ENO always has the same signal state as EN. Status word BR CC 1 CC 0 OV OS OR STA RLO /FC writes: 1 - - - - 0 1 1 1 Example Q 4.0 I 0.0 MW10 I_DINT ENO EN IN OUT MD12 NOT If I0.0 is "1", then the content of MW10 is read as an integer and converted to a double integer. The result is stored in MD12. The output Q4.0 is "1" if the conversion is not executed (ENO = EN = 0). Conversion Instructions 3.5 BCD_DI BCD to Double Integer Ladder Logic (LAD) for S7-300 and S7-400 Programming Reference Manual, 04/2017, A5E41524738-AA 43 3.5 BCD_DI BCD to Double Integer Symbol BCD_DI ENO EN IN OUT Parameter Data Type Memory Area Description EN BOOL I, Q, M, L, D Enable input ENO BOOL I, Q, M, L, D Enable output IN DWORD I, Q, M, L, D BCD number OUT DINT I, Q, M, L, D Double integer value of BCD number Description BCD_DI (Convert BCD to Double Integer) reads the content of the IN parameter as a seven-digit, BCD coded number (+/- 9999999) and converts it to a double integer value (32-bit). The double integer result is output by the parameter OUT. ENO always has the same signal state as EN. Status word BR CC 1 CC 0 OV OS OR STA RLO /FC writes: 1 - - - - 0 1 1 1 Example Q 4.0 I 0.0 MD8 BCD_DI ENO EN IN OUT MD12 NOT If I0.0 is "1" , then the content of MD8 is read as a seven-digit BCD coded number and converted to a double integer. The result is stored in MD12. The output Q4.0 is "1" if the conversion is not executed (ENO = EN = 0). Conversion Instructions 3.6 DI_BCD Double Integer to BCD Ladder Logic (LAD) for S7-300 and S7-400 Programming 44 Reference Manual, 04/2017, A5E41524738-AA 3.6 DI_BCD Double Integer to BCD Symbol DI_BCD ENO EN IN OUT Parameter Data Type Memory Area Description EN BOOL I, Q, M, L, D Enable input ENO BOOL I, Q, M, L, D Enable output IN DINT I, Q, M, L, D Double integer number OUT DWORD I, Q, M, L, D BCD value of a double integer number Description DI_BCD (Convert Double Integer to BCD) reads the content of the IN parameter as a double integer (32-bit) and converts it to a seven-digit BCD coded number (+/- 9999999). The result is output by the parameter OUT. If an overflow occurred, ENO will be "0". Status word BR CC 1 CC 0 OV OS OR STA RLO /FC writes: x - - x x 0 x x 1 Example Q 4.0 I 0.0 MD8 DI_BCD ENO EN IN OUT MD12 NOT If I0.0 is "1", then the content of MD8 is read as a double integer and converted to a seven-digit BCD number. The result is stored in MD12. The output Q4.0 is "1" if an overflow occurred, or the instruction was not executed (I0.0 = 0). Conversion Instructions 3.7 DI_REAL Double Integer to Floating-Point Ladder Logic (LAD) for S7-300 and S7-400 Programming Reference Manual, 04/2017, A5E41524738-AA 45 3.7 DI_REAL Double Integer to Floating-Point Symbol DI_REAL ENO EN IN OUT Parameter Data Type Memory Area Description EN BOOL I, Q, M, L, D Enable input ENO BOOL I, Q, M, L, D Enable output IN DINT I, Q, M, L, D Double integer value to convert OUT REAL I, Q, M, L, D Floating-point number result Description DI_REAL (Convert Double Integer to Floating-Point) reads the content of the IN parameter as a double integer and converts it to a floating-point number. The result is output by the parameter OUT. ENO always has the same signal state as EN. Status word BR CC 1 CC 0 OV OS OR STA RLO /FC writes: 1 - - - - 0 1 1 1 Example Q 4.0 I 0.0 MD8 DI_REAL ENO EN IN OUT MD12 NOT If I0.0 is "1", then the content of MD8 is read as an double integer and converted to a floating-point number. The result is stored in MD12. The output Q4.0 is "1" if the conversion is not executed (ENO = EN = 0). Conversion Instructions 3.8 INV_I Ones Complement Integer Ladder Logic (LAD) for S7-300 and S7-400 Programming 46 Reference Manual, 04/2017, A5E41524738-AA Yüklə 1,39 Mb. Dostları ilə paylaş:
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