The application of American SAMA diagrams and SAMA legends in automatic control design
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The SAMA diagram is an engineering configuration diagram developed by the Scientific Apparatus Makers Association. SAMA diagrams utilize symbols such as addition, subtraction, multiplication, division, differentiation, integration, OR gates, AND gates, disturbance-free switching, disturbance-induced switching, RS flip-flops, maximum value, minimum value, median value selection, three-way selection, upper limit setting, and lower limit setting, etc. to visually represent system control principles, control processes, constraints, and the designer’s conceptual approach. They also provide a convenient and intuitive means for automation engineers to optimize and improve control schemes. SAMA diagrams can clearly illustrate the control process, control algorithms, the designer’s concepts, and the relationships between system inputs and outputs. This feature is similar to that of DCS control configuration diagrams. Although the notation used in SAMA diagrams varies slightly among different companies, many elements of such notation are common, and major international instrument manufacturers use SAMA diagrams for designing control systems. Yunnan Changhui Instrument Manufacturing Co., Ltd. provides a CAD version of the SAMA legend in this article for everyone’s reference and learning.
This post was last edited by yunrun on March 1, 2017, at 17:32.
CAD version of SAMA legends:
Functions: Field equipment; Signal sources; Level transmitters; Pressure transmitters.
Descriptions: Analog inputs from the field; Field signal inputs; Level transmitters; Pressure transmitters.
Functions: Flow transmitters; Position transmitters; Temperature transmitters; Composition analysis transmitters.
Descriptions: Flow transmitters; Position transmitters; Temperature transmitters; Composition analysis transmitters.
Link: yunrun.com.cn/tech/1255.html
Functions: Rate transmitters; Temperature measuring elements; Pressure measuring elements; Flow measuring elements.
Descriptions: Rate transmitters; Temperature sensors; Pressure sensors; Flow sensors.
Functions: Level measuring elements; Display; Recording; Relay coils.
Descriptions: Level measuring sensors; Display of measured values; Recording of measured values; Connection to relay coils.
Functions: Pneumatic power source; Signal connection symbols; Current/voltage converters; Resistance/current converters.
Descriptions: Pneumatic power source for pneumatic instruments and equipment; Symbols for connecting to logic diagrams; Conversion of current to voltage; Conversion of resistance to current.
Functions: Pneumatic pressure/current converters; Voltage/current converters; Current/pneumatic pressure converters; Voltage/pneumatic pressure converters.
Descriptions: Conversion of pneumatic pressure values to electrical signals; Conversion of voltage values to electrical signals; Conversion of current to pneumatic pressure values; Conversion of voltage to pneumatic pressure.
Functions: Digital/logic converters; Voltage/voltage converters; Pneumatic pressure/voltage converters; Logic/digital converters.
Descriptions: Digital/logic conversion; Conversion of voltage to another voltage signal; Conversion of pneumatic pressure values to electrical signals; Logic/digital conversion.
Functions: Contact/logic converters; Analog-to-digital converters; Digital-to-analog converters; Signal tracking.
Descriptions: Switching signal/logic conversion; Analog-to-digital conversion; Digital-to-analog conversion; Signal tracking.
Functions: Pulse/current converters; Pulse/pulse converters; Normally open contacts; Normally closed contacts.
Descriptions: Conversion of pulses to current signals; Conversion between pulse signals; Normally open switching signals; Normally closed switching signals.
Links: http://yunrun.com.cn/upload/201702/16/201702161431037039.png; http://yunrun.com.cn/upload/201702/16/201702161431155007.png
Functions: Time relays; Electromagnetic coil drivers; Electric actuators; Hydraulic actuators.
Descriptions: Delayed start/stop; Actuators powered by electricity; Actuators powered by hydraulic pressure.
Links: http://yunrun.com.cn/upload/201702/16/201702161431297820.png; http://yunrun.com.cn/upload/201702/16/201702161431434226.png; http://yunrun.com.cn/upload/201702/16/201702161431530164.png; http://yunrun.com.cn/upload/201702/16/201702161432035007.png
Functions: Linear stroke valves; Three-way valves; Angular stroke valves; Rotary ball valves.
Descriptions: Compatible with linear stroke actuators; Compatible with angular stroke actuators.
Links: http://yunrun.com.cn/upload/201702/16/201702161432142820.png; http://yunrun.com.cn/upload/201702/14/201702142043142097.png; http://yunrun.com.cn/upload/201702/14/201702142044333660.png; http://yunrun.com.cn/upload/201702/14/201702142045523503.png
Functions: Pneumatic actuators; Summation; Averaging; Difference calculation.
Descriptions: Powered by compressed air; Output equals the algebraic sum of all inputs; Output equals the algebraic difference between two inputs.
Links: http://yunrun.com.cn/upload/201702/14/201702142047491785.png; http://yunrun.com.cn/upload/201702/16/201702161426169539.png; http://yunrun.com.cn/upload/201702/14/201702142050365847.png
Functions: Proportional control; Inverse proportional control; Integration.
Descriptions: Output is directly proportional to input; Output equals the negative of input; Output changes are related to the integral of input magnitude over time.
Links: http://yunrun.com.cn/upload/201702/14/201702142052339753.png; http://yunrun.com.cn/upload/201702/14/201702142052422253.png; http://yunrun.com.cn/upload/201702/14/201702142055296316.png; http://yunrun.com.cn/upload/201702/14/201702142055420066.png
Functions: Differentiation; Multiplication; Division; Square root calculation.
Descriptions: Output is proportional to the rate of change of input; Output equals the product of two inputs; Output equals the quotient of two inputs; Output equals the square root of input.
Links: http://yunrun.com.cn/upload/201702/14/201702142057419285.png; http://yunrun.com.cn/upload/201702/14/201702142057503972.png; http://yunrun.com.cn/upload/201702/14/201702142059460222.png; http://yunrun.com.cn/upload/201702/14/201702142059554910.png
Functions: Function generators; Time functions; Selection of maximum/minimum values.
Descriptions: Output equals a nonlinear or arbitrary function of input; Output equals the larger/smaller value among multiple inputs.
Links: http://yunrun.com.cn/upload/201702/14/201702142101559285.png; http://yunrun.com.cn/upload/201702/14/201702142102387253.png; http://yunrun.com.cn/upload/201702/14/201702142107027253.png; http://yunrun.com.cn/upload/201702/14/201702142111446316.png
Functions: Upper/lower limit settings; No specified actuator type.
Descriptions: Output equals the smaller/larger value between input and limit values.
Links: http://yunrun.com.cn/upload/201702/14/201702142114577878.png; http://yunrun.com.cn/upload/201702/16/201702162136512507.png; http://yunrun.com.cn/upload/201702/14/201702142111542253.png; http://yunrun.com.cn/upload/201702/14/201702142114358816.png
Functions: Selection of median values; Deviation calculation; Positive/negative deviations.
Descriptions: Output equals values excluding maximum/minimum values; Output equals input minus a certain value.
Links: http://yunrun.com.cn/upload/201702/14/201702142118463191.png; http://yunrun.run.com.cn/upload/201702/14/201702142118546785.png; http://yunrun.com.cn/upload/201702/14/201702142124125691.png; http://yunrun.com.cn/upload/201702/14/201702142124202410.png
Functions: High/low value monitors; Automatic adjustment.
Descriptions: Output state changes when input exceeds/falls below predefined limits.
Links: http://yunrun.com.cn/upload/201702/14/201702142126366785.png; http://yunrun.com.cn/upload/201702/14/201702142139317566.png; http://yunrun.com.cn/upload/201702/16/201702161426315476.png; http://yunrun.com.cn/upload/201702/14/201702142130130847.png
Functions: Automatic switching; Alarms in DCS systems; Manual adjustment operations.
Descriptions: Manual switching between manual and automatic control modes; Includes setpoint functionality.
Links: http://yunrun.com.cn/upload/201702/14/201702142134033035.png; http://yunrun.com.cn/upload/201702/16/201702161652043445.png; http://yunrun.com.cn/upload/201702/14/201702142139415378.png; http://yunrun.com.cn/upload/201702/14/201702142144011003.png
Functions: Manual switching; DCS devices/components; Representation of switching signals in analog circuits.
Links: http://yunrun.com.cn/upload/201702/14/201702142148531628.png; http://yunrun.com.cn/upload/201702/14/201702142149022253.png
Functions: Logical NOT operation; R/S flip-flops (reset-priority type).
Links: http://yunrun.com.cn/upload/201702/14/201702142134179285.png; http://yunrun.com.cn/upload/201702/14/201702142137134910.png; http://yunrun.com.cn/upload/201702/14/201702142146079753.png
Functions: Proportional/integral/differential controllers; Proportional/integral controllers; Logical AND operation.
Links: http://yunrun.com.cn/upload/201702/14/201702142146168816.png; http://yunrun.com.cn/upload/201702/14/201702142152004753.png
Functions: Logical OR operation; Signal crossover.
Description: Signals intersect and are connected at crossover points； (No dot at the intersection) Intersecting but not connected. Applications and training of SAMA diagrams. PID single-loop control systems are the most widely used in industrial automation; their control principle involves feeding the field measurement values into a PID regulator, where PID control calculations are performed to generate a control signal, which is then sent to the actuator to enable automatic control. The SAMA diagram of this single-loop PID control system is shown in Figure 1: http://yunrun.com.cn/upload/201702/16/201702161850370007.png (1) These are the water level, temperature, and flow rate transmitters, all of which are analog input signals. (2) For deviation alarm, that is, when the absolute value of the difference between the measured value and the set value exceeds a certain threshold, a logic 1 signal is output. Bias alarms are used because when, during the actual adjustment process, the difference between the controlled value and the set value becomes too large, it may indicate that there is a problem with the control system. In such cases, automatic mode should be disabled so that the output remains at its last automatic value; only once the difference between the measured value and the set value returns to a normal range should automatic mode be reactivated. Hexagon 1 here is a symbol for logical diagram connections. The output of (3) is the setpoint of the regulator. (4) This section includes the PID regulator and output upper and lower limiting. (5) is tracking. The actual valve position feedback value is (10). Since the control room is equipped with an operator station or a manual operator, the valve position feedback value fed into the DCS field control station is the signal converted by the manual operator, namely the external tracking signal (5) in the diagram. This signal functions as an analog input signal for the DCS system; it is an analog input of 1-5V or 4-20mA type. (6) It is a symbol connected to the logic diagram; it represents an external tracking switch. When its output is logic 1, the PID module is in tracking mode, and the output of the PID module equals the valve position feedback value (external tracking signal) ； When the output logic is 0, the PID module resumes normal operation, and the output is the result of the PID calculation. (7) It is a deviation alarm: when there is a large difference between the output of the PID algorithm and the valve position feedback value (the actual output of the field actuator), it may indicate a fault in the operator or the field actuator. In such cases, an alarm signal is sent, and the logic circuit switches the system from automatic to manual mode; the output remains unchanged or can be adjusted manually. (8) is a symbol connected to the logic diagram, which indicates the “automatic/manual” mode of the operator. When the state of hexagon 5 is logic 0, it indicates that the hand operator is in manual mode, and the control amount is adjusted manually ； When the status is logic 1, it indicates that the manual operator is in automatic mode, and the system’s output is controlled by the PID module. (9) Are symbols connected to the logic diagram. It switches from programmed to manual mode ； It switches from programmed to automatic. (10) It is the actual feedback signal, which is related to the manual operator; if no manual operator is used, it is directly fed into the DCS system as the actual valve position feedback signal.
CAD version of SAMA legends:
Functions: Field equipment; Signal sources; Level transmitters; Pressure transmitters.
Descriptions: Analog inputs from the field; Field signal inputs; Level transmitters; Pressure transmitters.
Functions: Flow transmitters; Position transmitters; Temperature transmitters; Composition analysis transmitters.
Descriptions: Flow transmitters; Position transmitters; Temperature transmitters; Composition analysis transmitters.
Link: yunrun.com.cn/tech/1255.html
Functions: Rate transmitters; Temperature measuring elements; Pressure measuring elements; Flow measuring elements.
Descriptions: Rate transmitters; Temperature sensors; Pressure sensors; Flow sensors.
Functions: Level measuring elements; Display; Recording; Relay coils.
Descriptions: Level measuring sensors; Display of measured values; Recording of measured values; Connection to relay coils.
Functions: Pneumatic power source; Signal connection symbols; Current/voltage converters; Resistance/current converters.
Descriptions: Pneumatic power source for pneumatic instruments and equipment; Symbols for connecting to logic diagrams; Conversion of current to voltage; Conversion of resistance to current.
Functions: Pneumatic pressure/current converters; Voltage/current converters; Current/pneumatic pressure converters; Voltage/pneumatic pressure converters.
Descriptions: Conversion of pneumatic pressure values to electrical signals; Conversion of voltage values to electrical signals; Conversion of current to pneumatic pressure values; Conversion of voltage to pneumatic pressure.
Functions: Digital/logic converters; Voltage/voltage converters; Pneumatic pressure/voltage converters; Logic/digital converters.
Descriptions: Digital/logic conversion; Conversion of voltage to another voltage signal; Conversion of pneumatic pressure values to electrical signals; Logic/digital conversion.
Functions: Contact/logic converters; Analog-to-digital converters; Digital-to-analog converters; Signal tracking.
Descriptions: Switching signal/logic conversion; Analog-to-digital conversion; Digital-to-analog conversion; Signal tracking.
Functions: Pulse/current converters; Pulse/pulse converters; Normally open contacts; Normally closed contacts.
Descriptions: Conversion of pulses to current signals; Conversion between pulse signals; Normally open switching signals; Normally closed switching signals.
Links: http://yunrun.com.cn/upload/201702/16/201702161431037039.png; http://yunrun.com.cn/upload/201702/16/201702161431155007.png
Functions: Time relays; Electromagnetic coil drivers; Electric actuators; Hydraulic actuators.
Descriptions: Delayed start/stop; Actuators powered by electricity; Actuators powered by hydraulic pressure.
Links: http://yunrun.com.cn/upload/201702/16/201702161431297820.png; http://yunrun.com.cn/upload/201702/16/201702161431434226.png; http://yunrun.com.cn/upload/201702/16/201702161431530164.png; http://yunrun.com.cn/upload/201702/16/201702161432035007.png
Functions: Linear stroke valves; Three-way valves; Angular stroke valves; Rotary ball valves.
Descriptions: Compatible with linear stroke actuators; Compatible with angular stroke actuators.
Links: http://yunrun.com.cn/upload/201702/16/201702161432142820.png; http://yunrun.com.cn/upload/201702/14/201702142043142097.png; http://yunrun.com.cn/upload/201702/14/201702142044333660.png; http://yunrun.com.cn/upload/201702/14/201702142045523503.png
Functions: Pneumatic actuators; Summation; Averaging; Difference calculation.
Descriptions: Powered by compressed air; Output equals the algebraic sum of all inputs; Output equals the algebraic difference between two inputs.
Links: http://yunrun.com.cn/upload/201702/14/201702142047491785.png; http://yunrun.com.cn/upload/201702/16/201702161426169539.png; http://yunrun.com.cn/upload/201702/14/201702142050365847.png
Functions: Proportional control; Inverse proportional control; Integration.
Descriptions: Output is directly proportional to input; Output equals the negative of input; Output changes are related to the integral of input magnitude over time.
Links: http://yunrun.com.cn/upload/201702/14/201702142052339753.png; http://yunrun.com.cn/upload/201702/14/201702142052422253.png; http://yunrun.com.cn/upload/201702/14/201702142055296316.png; http://yunrun.com.cn/upload/201702/14/201702142055420066.png
Functions: Differentiation; Multiplication; Division; Square root calculation.
Descriptions: Output is proportional to the rate of change of input; Output equals the product of two inputs; Output equals the quotient of two inputs; Output equals the square root of input.
Links: http://yunrun.com.cn/upload/201702/14/201702142057419285.png; http://yunrun.com.cn/upload/201702/14/201702142057503972.png; http://yunrun.com.cn/upload/201702/14/201702142059460222.png; http://yunrun.com.cn/upload/201702/14/201702142059554910.png
Functions: Function generators; Time functions; Selection of maximum/minimum values.
Descriptions: Output equals a nonlinear or arbitrary function of input; Output equals the larger/smaller value among multiple inputs.
Links: http://yunrun.com.cn/upload/201702/14/201702142101559285.png; http://yunrun.com.cn/upload/201702/14/201702142102387253.png; http://yunrun.com.cn/upload/201702/14/201702142107027253.png; http://yunrun.com.cn/upload/201702/14/201702142111446316.png
Functions: Upper/lower limit settings; No specified actuator type.
Descriptions: Output equals the smaller/larger value between input and limit values.
Links: http://yunrun.com.cn/upload/201702/14/201702142114577878.png; http://yunrun.com.cn/upload/201702/16/201702162136512507.png; http://yunrun.com.cn/upload/201702/14/201702142111542253.png; http://yunrun.com.cn/upload/201702/14/201702142114358816.png
Functions: Selection of median values; Deviation calculation; Positive/negative deviations.
Descriptions: Output equals values excluding maximum/minimum values; Output equals input minus a certain value.
Links: http://yunrun.com.cn/upload/201702/14/201702142118463191.png; http://yunrun.run.com.cn/upload/201702/14/201702142118546785.png; http://yunrun.com.cn/upload/201702/14/201702142124125691.png; http://yunrun.com.cn/upload/201702/14/201702142124202410.png
Functions: High/low value monitors; Automatic adjustment.
Descriptions: Output state changes when input exceeds/falls below predefined limits.
Links: http://yunrun.com.cn/upload/201702/14/201702142126366785.png; http://yunrun.com.cn/upload/201702/14/201702142139317566.png; http://yunrun.com.cn/upload/201702/16/201702161426315476.png; http://yunrun.com.cn/upload/201702/14/201702142130130847.png
Functions: Automatic switching; Alarms in DCS systems; Manual adjustment operations.
Descriptions: Manual switching between manual and automatic control modes; Includes setpoint functionality.
Links: http://yunrun.com.cn/upload/201702/14/201702142134033035.png; http://yunrun.com.cn/upload/201702/16/201702161652043445.png; http://yunrun.com.cn/upload/201702/14/201702142139415378.png; http://yunrun.com.cn/upload/201702/14/201702142144011003.png
Functions: Manual switching; DCS devices/components; Representation of switching signals in analog circuits.
Links: http://yunrun.com.cn/upload/201702/14/201702142148531628.png; http://yunrun.com.cn/upload/201702/14/201702142149022253.png
Functions: Logical NOT operation; R/S flip-flops (reset-priority type).
Links: http://yunrun.com.cn/upload/201702/14/201702142134179285.png; http://yunrun.com.cn/upload/201702/14/201702142137134910.png; http://yunrun.com.cn/upload/201702/14/201702142146079753.png
Functions: Proportional/integral/differential controllers; Proportional/integral controllers; Logical AND operation.
Links: http://yunrun.com.cn/upload/201702/14/201702142146168816.png; http://yunrun.com.cn/upload/201702/14/201702142152004753.png
Functions: Logical OR operation; Signal crossover.
Description: Signals intersect and are connected at crossover points； (No dot at the intersection) Intersecting but not connected. Applications and training of SAMA diagrams. PID single-loop control systems are the most widely used in industrial automation; their control principle involves feeding the field measurement values into a PID regulator, where PID control calculations are performed to generate a control signal, which is then sent to the actuator to enable automatic control. The SAMA diagram of this single-loop PID control system is shown in Figure 1: http://yunrun.com.cn/upload/201702/16/201702161850370007.png (1) These are the water level, temperature, and flow rate transmitters, all of which are analog input signals. (2) For deviation alarm, that is, when the absolute value of the difference between the measured value and the set value exceeds a certain threshold, a logic 1 signal is output. Bias alarms are used because when, during the actual adjustment process, the difference between the controlled value and the set value becomes too large, it may indicate that there is a problem with the control system. In such cases, automatic mode should be disabled so that the output remains at its last automatic value; only once the difference between the measured value and the set value returns to a normal range should automatic mode be reactivated. Hexagon 1 here is a symbol for logical diagram connections. The output of (3) is the setpoint of the regulator. (4) This section includes the PID regulator and output upper and lower limiting. (5) is tracking. The actual valve position feedback value is (10). Since the control room is equipped with an operator station or a manual operator, the valve position feedback value fed into the DCS field control station is the signal converted by the manual operator, namely the external tracking signal (5) in the diagram. This signal functions as an analog input signal for the DCS system; it is an analog input of 1-5V or 4-20mA type. (6) It is a symbol connected to the logic diagram; it represents an external tracking switch. When its output is logic 1, the PID module is in tracking mode, and the output of the PID module equals the valve position feedback value (external tracking signal) ； When the output logic is 0, the PID module resumes normal operation, and the output is the result of the PID calculation. (7) It is a deviation alarm: when there is a large difference between the output of the PID algorithm and the valve position feedback value (the actual output of the field actuator), it may indicate a fault in the operator or the field actuator. In such cases, an alarm signal is sent, and the logic circuit switches the system from automatic to manual mode; the output remains unchanged or can be adjusted manually. (8) is a symbol connected to the logic diagram, which indicates the “automatic/manual” mode of the operator. When the state of hexagon 5 is logic 0, it indicates that the hand operator is in manual mode, and the control amount is adjusted manually ； When the status is logic 1, it indicates that the manual operator is in automatic mode, and the system’s output is controlled by the PID module. (9) Are symbols connected to the logic diagram. It switches from programmed to manual mode ； It switches from programmed to automatic. (10) It is the actual feedback signal, which is related to the manual operator; if no manual operator is used, it is directly fed into the DCS system as the actual valve position feedback signal.
Just looking at this thing makes me want to…~~~
It’s damaged and cannot be repaired; the original poster, please make another one
Thank you to the original poster for sharing: handshake