Modular power meter: MODBUS-RTU™ addressing.The address of the first module is configurable by the client, but the factory setting defaults to 1.Each successive module gets the address of the former + 1. Intervention nor set-up is necessary to achieve this addressing scheme. Every second, a scan is started that checks if there are modules added or removed. The MODBUS input goes to 2 receivers, one at a fixed baud rate of 9600bd, and one on a flexible data rate (2400 to 115200bd). This assures that a user can always connect to the sensor on 9600bd. The flexible data rate receiver follows the speed of a MODBUS query. To figure out the right speed, up-to 8 MODBUS query's can be lost (=no response is returned). The modbus response follows always the speed of the query packet. The packet format is binary 8-bit + 16-bit CRC. An internally 120 Ohm, non removeable, termination-resistor is integrated into the module. |
