Emerson 3-9000-771A Table 3-4Serial Port A parameters, Description, Common features, Serial connections, Port/Communication

Daniel 3818 LNG Liquid Ultrasonic Meter Installation Manual	Section 3: Electrical installation
3-9000-771 Rev A	May 2012

Serial connections

Use serial cable (Daniel P/N 3-2500-401) to connect to a PC running Daniel MeterLink. The cable is designed for RS-232 communications which is the serial Port A default configuration (see Appendix A field wiring diagram, Daniel Drawing DMC-004936). The DB-9 end of the cable plugs directly into the PC running Daniel MeterLink. The three wires on the other end of the cable connect to the CPU Module. The RED wire goes to RX, the WHITE wire goes to TX, and the BLACK wire goes to COM for the RS-485/RS-232 treenails (Table 3-4for Port A wiring).

When Beldon wire No. 9940 or equivalent is used, the maximum cable length for RS-232 communications at 9600 bps is 88.3 meters (250 ft.) and the maximum cable length for RS-485 communication at 57600 bps is 600 meters (1970 ft.).

Port A supports a special override mode which forces the port to use known communication values (19200 baud, address 32, RS-232). Note that the protocol is auto-detected. This mode is expected to be used during meter commissioning (to establish initial communication) and in the event that the user cannot communicate with the meter (possibly due to an inadvertent communication configuration change). Alternately, when using Daniel MeterLink™ with an Ethernet port, use Ethernet cable (Daniel P/N 3-3400-079) to connect the PC.

Table 3-4 Serial Port A parameters

Port/Communication		Description	Common features
Port A (Standard)		• Typically used for general communications with	• Communications via Daniel MeterLink
•	RS-232	a flow computer, RTU (Modbus slave) and		using RS-232 or RS-485 Full Duplex
•	RS-485 Half Duplex	radios.	•	Software configurable Modbus
•	RS-485 Full Duplex	• Special override mode to force port configura-		Address (1-247)
		tion to known settings.	• Auto-detects TCP/IP and ASCII or RTU
		• Supports RTS/CTS handshaking with software-		Protocol
		configurable RTS on/off delay times.		-	ASCII Protocol:
		• Factory default is RS-232, Address 32, 19200
					Start Bits = 1, Data Bits=71
		baud.
				- Parity: odd or even 1, Stop Bits = 11
				- Baud Rates: 1200, 2400, 9600,
					19200, 38400, 57600, 115000 bps
				- RTU Protocol:
					Start Bits = 1, Data Bits=81
				- Parity: none, Stop Bits = 11
				- Baud Rates: 1200, 2400, 9600,
					19200, 38400, 57600, 115000 bps
Ethernet		• Preferred port for diagnostic communication	•	Modbus TCP/IP
		via Daniel MeterLink
		• 10 Mbps/100 Mbps

1.Denotes auto-detected protocols

CPU Module labeling and LED indicators 45