Siemens STEP 7-MicroWIN SMART Usage Guide (Example PLC: S7-200 SMART)

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1. Wiring Instructions

1.1 Cabinet Wiring

1.2 UC04 Wiring

1.3 RS485 Servo Wiring

PLC-A	RS485 Servo-A
PLC-B	RS485 Servo-B
Power+	RS485 Servo+
Power- (must share GND with PLC)	RS485 Servo-

2. Program Instructions

2.1 Function Block Packet Library

1. Siemens S7-200 SMART with the Fashion Star bus servo communication protocol library (protocol reference: https://fashionstar.com.hk/).

(Function block library)

1. Using the Angle Control Library as an example: TX_0 to TX_CS are the actual protocol registers to send. BYTE uses one byte and WORD uses two bytes (see the diagram "Angle Control Library Register Description"). Note: in the angle control library, ANGLE and TIME occupy four registers. For other fields, follow the data type in the register description. TX_V is the register head, such as VB100, VB200, VB300... (see sample program below).

   • ID: servo ID
   • ANGLE: servo angle (unit 0.1°, for 90° set 900)
   • TIME: movement time (ms)
   • POWER: running power (mW)
   • ACC: acceleration time (ms)
   • DEC: deceleration time (ms)

(Angle control library)

(Angle control library register description)

2.2 Program Analysis for Function Block Packet Library

1. Port 0 output: SMB30 = 2#10011001 (freeport communication, 115200 baud, 8 data bits, no parity).

(SMB30/SMB130 setting reference)

1. Library parameter explanation:

   • ID = 0: control servo #0
   • ANGLE = 900: set angle to 90° (unit 0.1°)
   • TIME = 100: move to 90° in 100ms
   • POWER = 0: output power 0mW
   • ACC = 20: acceleration time 20ms
   • DEC = 20: deceleration time 20ms
   • TX_0 = VB101
   • TX_1 = VB102
   • TX_CID = VB103
   • TX_LONG = VB104
   • TX_ID = VB105
   • TX_ANGLE = VW106
   • TX_TIME = VW110
   • TX_ACC = VW114
   • TX_DEC = VW116
   • TX_POWER = VW118
   • TX_CS = VW120
   • TX_V = VB100

1. Use XMT for send and RCV for receive. TBL is the send register table; PORT is the send port (port 0 in this example). The program uses timer T32 for scheduled sending, with a |N| falling-edge trigger to send once and avoid redundant repeated sends.