Chapter 2 External I/O Specification I/O Signal Specifications of Old Circuit Board 2 Specification for I/O Signals (I/O Power (VCC_EX)/SG Not Separated) 1 The sink current is limited by the current limiting resistor (R = 1 kΩ). 2 Do not use this as a drive for a high-current load such as a coil. 3 This voltage depends on the pull-up resistance (Rpu = 10 kΩ) of the printer and the input resistance of the external device. 21 CAUTION • Regardless of whether an external device is connected or the connected external device is turned on or off, when the printer is turned on, the voltage and signal are output from the I/O power (VCC EX) pin and output signal pin of the external I/O connector.
Connect an external _ device under this assumption. • If connecting to an external device, make sure that the printer I/O power (VCC EX) and _ external device I/O power are the same voltage. ∗ When I/O power (VCC EX) and SG are not separated _ The I/O power (VCC EX) on the printer side is 5 V. Use 5 V also for the I/O power on the _ external device side. ∗ When I/O power (VCC EX) and SG are separated _ The printer side I/O power (VCC EX) is the voltage supplied from the external device side. _ Use this same voltage for the I/O power on the external device side. Q NOTE The I/O terminals are indefinite during the following conditions.
• When I/O power (VCC EX) and SG are not separated _ ∗ Immediately after turning the power on ∗ During power off processing ∗ When the power is off • When I/O power (VCC EX) and SG are separated _ ∗ Before providing I/O power on printer side Input/Output Item Value Input signal to the printer Input port on the printer Support for an open drain or open collector output Low level VIL max. 0.8 V _ Sink current Min. 2 mA Max. 7 mA *1 High level (Allowable leakage current) Max. 10 uA Output signal from printer Output port on the printer Open collector output (pull-up resistor is on the printer) Low level VOL max. 0.8 V _ Sink current Max. 1.8 mA *2 High level VOH min. 4.0 V *3 _