User's Manual

Table Of Contents
ACCEL-7450 User's Manual
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4 RTS Request to Send OUT * *
7 SG Signal Ground —— O O
20 DTR Data Terminal Ready OUT O O
O: USE X: NOT USE *: HIGH LEVEL
Signal description:
Prescription of signal level on RS-232C
1=Low (Mark): -25 ~ -3 V
0=High (Space): +3 ~ +25V
RDY/BSY protocol (RS-232C)
PIN 1 FG (Frame Ground — connect to the printer rack
Connect to the circuit frame ground
PIN 3 RD (Received Data)
Receive serial data from the computer through this pin. This pin is low level when it receives no
data.
PIN 7 SG (Signal Ground)
Connect to the signal ground
PIN 20 DTR (Data Terminal Ready)
This pin is high level when the printer is ready to receive data. It is low level when not ready to
receive data.
X-ON/X-OFF Protocol (RS-232C)
PIN 1 FG (Frame Ground---connect to the printer rack)
Connect to the circuit frame ground.
PIN 2 SD (Transmitted Data)
Send serial data to the printer through this pin. This pin is low level when it receives no data.
PIN 3 RD (Received Data)
Receive serial data from the printer through this pin. This pin is low level when it receives no
data.
PIN 4 RTS (Request to Send)
Send Request to send signal from the printer. This pin is high level when the printer is turned
on.
PIN 7 SG (Signal Ground)
Connect to the signal ground.
PIN 20 DTR (Data Terminal Ready)
Output the signal from the printer. This pin is high level when the printer is turned on.