• The GP’s RS-485(RS-422) port is not isolated, therefore, be sure
to connect pin #7 (SG terminal) to the other unit's signal
ground terminal. If this is not done, the RS-485(RS-422) circuit
may be damaged.
• Since pin #14 (VCC) is not protected, be sure to use it only
within its rated range.
When making a cable, please be aware of the following:
<For RS-232C >
• Do not connect #9 (TRMX), #10 (RDA), #11 (SDA), #15 (SDB), #16 (RDB),
#18(CSB), #19 (ERB), #21 (CSA), and #22 (ERA).
<For RS-422 >
• The following pairs of pin numbers must be connected (shorted):
#18(CSB) <-> #19 (ERB)
#21(CSA) <-> #22 (ERA)
• Connecting the #9 (TRMX) and #10 (RDA) wires adds a termination resistance of
100
Ω
Ω
Ω
Ω
Ω
between RDA and RDB.
• Use a 4-wire cable when the PLC type is Memory Link and the cable is RS-422.
<External Buzzer Output>
• Use pins 23(BUZZ GND) and 25(BUZZ OUT) when producing external output for
an alarm.
This output circuit does not contain fuses. If used, Pro-face recommends the design
of an external safety circuit. (GP units Revision P or later)
To confirm your GP unit’s Revision, refer to "Revision Information".
External Buzzer Output
Buzzer
Can drive a buzzer
of DC5V to
DC24V, at up to
0.3A.
Internal
Circuit
SIO 25 Pin
SIO 23 Pin
GP-37WB Unit
Optical Isolation
