Issue
Requirement to connect multiple sub meter displays to the Enercept meter.

Product Line
PowerLogic Enercept meter, Sub Meter Display (SMD or SMDOPN)

Environment
Daisy chain wiring for communications

Cause
Requires to have multiple displays at different locations for remote monitoring of the data from the meter.

Resolution
Yes, multiple sub meter displays can be connected to an Enercept meter in order to monitor the voltage, current, power, power factor and energy parameters.

The display resides on a Modbus network as a pass-through device. It provides an upstream and downstream communication connection. This allows for flexible data retrieval as the upstream options include RS-232 or RS-485.



As shown in both figures, the SMD [sub meter display] has two RS-485 serial ports; an upstream and a downstream terminal. The upstream terminal is primarily used for multiple or additional sub meter displays and computers for monitoring while the downstream terminal is used to connect multiple monitoring devices/meters on the daisy-chain.

Downstream Devices
Observe these guidelines for downstream devices communications wiring:
• Connect devices on a daisy chain from the downstream RS-485 port.
• The display can support 32 devices with a maximum distance of 4000ft. (1,219 m) to the last device.
• For devices on the daisy chain, follow the device distance limitations recommended by the manufacturer.
• Each device must have a unique address.
• The last device must be terminated with a terminator (Square D part no. 3090MCTAS485 or 100 ohm resistor).

Upstream Devices
Observe these guidelines for upstream devices communications wiring:
• A client computer or additional Sub Meter Displays can be connected on a daisy chain to the upstream RS-485 port.
• The maximum distance from the first upstream device to the last is 4000 ft. (1,219 m).
• Each device on this upstream connection as well as those downstream must have a unique address.
• The last upstream device must be terminated with a terminator (Square D PN 3090MCTAS485 or 100 ohm resistor).



The SMD is the sub meter display mounted in an enclosure.
The SMDOPN is the open style submeter display without an enclosure.