ECT 464Slide 2Introduction to SiemensSiemens OverviewSiemens Scan CycleData Sizes and AddressingSlide 7Slide 8Data Types and AddressingTimers and AddressingSlide 11Counters and AddressingHigh Speed Counters and AddressingAccumulatorsSlide 15Special BitsSlide 17Slide 18Sequence Control RelaysFloating PointStringsConstantsAddressing the Local and Expansion I/OSlide 24Using Pointers for Indirect AccessingSlide 26Modifying a PointerOther LimitationsSpecial Features of the S7-224ECT 464 ECT 464 Lecture 21Lecture 21Introduction to SiemensIntroduction to SiemensToday’s Quote:Today’s Quote:The trouble with the guy who talks The trouble with the guy who talks too fast is that he often says too fast is that he often says something he hasn’t thought of something he hasn’t thought of yet. yet. Do not be quick with your mouth, Do not be quick with your mouth,  do not be hasty in your heart  do not be hasty in your heart  to utter anything before God.  to utter anything before God.  God is in heaven  God is in heaven  and you are on earth,  and you are on earth,  so let your words be few. so let your words be few. Ecclesiastes 5:2Ecclesiastes 5:2Introduction to SiemensIntroduction to SiemensThe S7-224 is a micro-programmable logic controller (Micro PLC) that can control a variety of automation applications. Compact design, low cost, and a powerful instruction set make the S7-224 a perfect solution for controlling small applications.Siemens OverviewSiemens Overview•32 bit architecture32 bit architecture•Different File/Data TypesDifferent File/Data Types•Additional Programming LanguagesAdditional Programming Languages•AC PowerAC Power•14 DC Inputs14 DC Inputs•10 Relay Outputs10 Relay Outputs•Program Memory 12288 bytesProgram Memory 12288 bytes•Data Memory 8192 bytesData Memory 8192 bytes•Seven Expansion ModulesSeven Expansion Modules•High Speed Counters (6 single or 4 double)High Speed Counters (6 single or 4 double)•Real Time ClockReal Time Clock•Floating Point MathFloating Point Math•RS-485 communicationsRS-485 communications•0.22 useconds/instruction0.22 useconds/instruction•Digital I/O Image size 256 (128 In / 128 Out) Digital I/O Image size 256 (128 In / 128 Out)Siemens Scan CycleSiemens Scan CycleOnly has STOP and RUN modesData Sizes and AddressingData Sizes and AddressingTo access a bit in a memory area, you specify the address, which includes the memory area identifier, the byte address, and the bit number (“byte.bit” addressing). You can access data in most memory areas (V, I, Q, M, S, L, and SM) as bytes, words, or double words by using the byte-address format. To access a byte, word, or double word of data in the memory, you must specify the address in a way similar to specifying the address for a bit. This includes an area identifier, data size designation, and the starting byte address of the byte, word, or double-word value. Data in other memory areas (such as T, C, HC, and the accumulators) are accessed by using an address format that includes an area identifier and a device number.Data Sizes and AddressingData Sizes and AddressingData Sizes and AddressingData Sizes and AddressingData Types and AddressingData Types and AddressingProcess-Image Input Register: IBit: I[byte address].[bit address] I0.1 (I0.0-I15.7)Byte, Word, or Double Word: I[size][starting byte address] IB4Process-Image Output Register: QBit: Q[byte address].[bit address] Q1.1 (Q0.0-Q15.7)Byte, Word, or Double Word: Q[size][starting byte address] QB5Variable Memory Area: VYou can use V memory to store intermediate results of operations being performed by the control logic in your program. You can also use V memory to store other data pertaining to your process or task. You can access the V memory area in bits, bytes, words, or double words:Bit: V[byte address].[bit address] V10.2 (VB0-VB8191)Byte, Word, or Double Word: V[size][starting byte address] VW100Bit Memory Area: MBit: M[byte address].[bit address] M26.7 (M0.0-M31.7)Byte, Word, or Double Word: M[size][starting byte address] MD20Timers and AddressingTimers and AddressingThe S7-224 provides timers that count increments of time in resolutions (time-base increments) of 1 ms, 10 ms, or 100 ms. Two variables are associated with a timer:- Current value: this 16-bit signed integer stores the amount of time counted by the timer.- Timer bit: this bit is set or cleared as a result of comparing the current and the preset value.The preset value is entered as part of the timer instruction. You access both of these variables by using the timer address (T + timer number). Access to either the timer bit or the current value is dependent on the instruction used: instructions with bitoperands access the timer bit, while instructions with word operands access the current value.Timers and AddressingTimers and AddressingCounters and AddressingCounters and AddressingThe S7-224 provides three types of counters that count each low-to-high transition event on the counter input(s): one type counts up only, one type counts down only, and one type counts both up and down. Two variables are associated with a counter:- Current value: this 16-bit signed integer stores the accumulated count.- Counter bit: this bit is set or cleared as a result of comparing the current and the preset value. The preset value is entered as part of the counter instruction. You access both of these variables by using the counter address (C + counter number). Access to either the counter bit or the current value is dependent on the instruction used: instructions with bit operands access the counter bit, while instructions with word operands access the current value. (C0-C255)High Speed Counters and High Speed Counters and AddressingAddressingThe high-speed counters count high-speed events independent of the CPU scan. High-speed counters have a signed, 32-bit integer counting value (or current value). To access the countvalue for the high-speed counter, you specify the address of the high-speed counter, using the memory type (HC) and the counter number (such as HC0). The current value of the high-speed counter is a read-only value and can be addressed only as a double word (32 bits).Format: HC[high-speed counter number] HC1 (HC0-HC5)AccumulatorsAccumulatorsThe accumulators are read/write