12. Potentiometer voltage and installation
1. The potentiometer for detecting the vertical up-down position of the chair is connected to S5.
The voltage is low in the down direction with the lower limit of 0.2 V and higher, and high in the up direction with the upper limit
of 4.8 V and lower.
The voltage is measured in VDC by connecting the black test lead of the multimeter to the GND pin on the p.c.board, and the red lead to
the TP1 pin.
2. The potentiometer for detecting the reclining angle is connected to S6.
The voltage is low in the reclining direction with the lower limit of 0.2 V and higher, and high in the raising direction with the upper
limit of 4.8 V and lower.
The voltage is measured in VDC by connecting the black test lead of the multimeter to the GND pin on the p.c.board, and the red lead to
the TP2 pin.
3. The potentiometer for detecting the leg rest angle is connected to S7.
The voltage is low in the retracting direction, and high in the extending direction.
The voltage is measured in VDC by connecting the black test lead of the multimeter to the GND pin on the p.c.board, and the red lead to
the TP3 pin.
[Note] The important factor here is that the voltage changes smoothly according to the operation of the chair rather than the absolute
value of the voltage.
The symptom that there is little change in voltage near position limits (for example, the voltage stays around 0.2 V) indicates the
poor installation of the potentiometer onto the chair; the potentiometer should be reinstalled.
13. Functions of the LEDs and connectors on the p.c.board.
Color Function
LED 1 Green Ready-to-output indicator. The LED is off if a prohibit-all input is present right after power is on.
LED 2 Green Power LED. Indicates the power supply to the p.c.board.
LED 3 Red Limit status indicator. The LED is on while the slide SW is at the limit position.
LED 4 Amber Serial 3 transmission indicator. The LED is turned on when the flow of transmission current is detected.
The LED is off when data to be transmitted does not exist or if there is an open circuit.
LED 5 Characters When there is no setup or malfunction, the chair position is indicated (to the right).
When a mode is specified, the present mode is indicated.When there is some sort of malfunction, the
corresponding error code is indicated.At power-up, a program number is indicated.
Connector No. Function
S1-A S1-B SW input connector for chair operation. No. 10 is common.
S2-A S2-B
SW input connector for headrest operation. No. 6 is common.
S3-B 4-bit input terminal (for connection with Siela and other units).
S4-1 S4-2 Input connector for operation prohibition. Nos.1-2: Prohibits lowering. Nos. 3-4: Prohibits all the operations.
S5 Connector for the potentiometer for up/down operation.
S6 Connector for the potentiometer for the backrest.
S7 Connector for the potentiometer for the leg rest.
S8 Output connector for the relay board. (With a leg rest terminal, 12P)
S9 Output connector for dental light control
S10 Output connector for the relay board. (Without a leg rest terminal, 10P)
S11 Output connector for the relay board. (For leg rest, 3P)
S12 Communication connector (receive only). Nos. 2- 3: input, No. 1: 5 V No. 4: ground.
S13 Input connector for chair lowering prohibition
S14 Communication connector 1-2: Transmission 3-4: Reception
S15 Power input 14 VAC
11. LP switch function setup (LP or P3)
The LP (last position) operation SW can be set up as a regular preset switch.
[Setup procedure]
1. Slide the limit SW on the p.c.board to the limit position. The beeper sounds once.
2. Press the mode SW. The beeper stops sounding.
3. Press the P2 SW to set the LP SW as P3, or press the LP SW to set it as LP.
4. Slide the limit SW back to the normal position.
-5-
