GE EPM 5200, EPM 5300, EPM 5350 Network of Instruments and Long Distance Communication, Computer

CHAPTER 4: COMMUNICATION INSTALLATION

4.3: Network of Instruments and Long Distance Communication

The RS-485 Transceiver is required for a large network of instruments.

•In a two-wire connection, a maximum of 900 instruments can be included in the same network (Figure 4.7)

•In a four-wire connection, a maximum of 3600 instruments can be included in the same network (Figure 4.8).

			RS-485
DEVICE	32 UNITS	DEVICE	TRANSCEIVER
			(Acts as Repeater)
			32	COMPUTER
			TRANSCEIVERS
			RS-485
DEVICE	32 UNITS	DEVICE	TRANSCEIVER
			(Acts as Repeater)

Figure 4.7: 2-Wire RS-485 Communication Installation Connection with Transceiver

DEVICE	32 UNITS	DEVICE	RS-485
			TRANSCEIVER
			(Acts as Repeater)
			32	COMPUTER
			TRANSCEIVERS
DEVICE	32 UNITS	DEVICE	RS-485
			TRANSCEIVER
			(Acts as Repeater)

Figure 4.8: 4-Wire RS-485 Communication Installation Connection with Transceiver

Use modems (dedicated or dial-up) when the instruments are located at great distances. However, set the modem to auto answer at the recommended value of 1200 baud rate, if noise conditions exist. Also, flow control must be disabled.

GE Multilin EPM 5000 series Advanced Power Meters 23