The GPZ-4COTE daughter board provides:
Four analog loop start/ground start trunk circuits
Four Caller ID Circuits
Connector for GCD-4COTA Blade
Connector for GCD-LTA
The GPZ-4COTE consumes four trunk ports ranging between ports
001~400. The CN2 connector provides connection to four analog trunk
ports, which are polarity sensitive (tip-to-tip, ring-to-ring). The power
failure circuits (CN3), however, are not polarity sensitive.