Modhoppers are configured using the Modbus protocol to communicate properly with the AcquiSuite unit.
The three most important things to remember when creating a Modbus chain are:
Each Modbus device must have a unique MODBUS ID.
Modbus devices are connected in a daisy chain fashion (fig. 1). This means that the RS485 terminals from one device lands on the RS485 terminals of the next device. A second set of wires is then run to the next device, and so on.
The Modbus chain should be terminated with 120–150Ω 1/4W resistor.
The Modhopper comes with two units: a send and a receive. The receive unit is wired to the Modbus chain.
Connect the provided antennae. Avoid sharp bends in the antennae wire as this will degrade the performance of the unit.
After powering on the unit check that it is functioning as expected by checking the following LEDs (please refer to fig. 17):
Alive: blinks green once per second.
RS485RX/TX: should blink about once per second while Modhopper is hooked up to an AcquiSuite unit.
The Modbus address can be set by the Modbus Address dipswitches as shown in (fig.18)
The system setting dipswitches are a powerful set of tools that can assist you while you configure your Modhopper. The channel dipswitches can be used to specify the channel (0-6 only) to be used by the Modhoppers. This can be used to remove interference caused by multiple Modhopper pairs. Channel 7, with all three switches on, is not allowed.