■PMH300系列多功能电力网络仪表
PMH300多功能电力网络仪表是一种具有可编程测量、显示、数字通讯和电能脉冲输出等功能的多功能电力仪表,能够完成电量测量、电能计量、数据显示、采集及传输，可广泛应用变电站自动化，配电自动化、智能建筑、企业内部的电能测量、管理、考核。测量精度为级、实现LED 现场显示和远程RS-485数字接口通讯，采用MODBUS-RTU通讯协议。
PMH300系列多功能电力网络仪表 Types of digital communication: RS485 communication connection MODBUS/RTU communication protocol
Provide serial asynchronous half-work RS458 communication interface, using MOD-BUS-RTU protocol, all kinds of data information can be transmitted on the communication line. Up to 32 network power meters can be connected on one line at the same time. Each network power meter can set its communication address (Address No.). The communication terminal numbers of different series of meters are different. The communication connection should use copper The shielded twisted pair of the net, the wire diameter is not less than 0.5mm. When wiring, you should use communication cables away from strong electric cables or other strong electric fields. It is recommended to use a network connection method, and it is not recommended to use star or other connection methods.
MODBUS protocol adopts the communication connection mode of master-slave response mode on a communication line. First, the signal of the host computer is addressed to a terminal device (slave) with only the address, and then the response signal sent by the terminal device is transmitted to the host in the opposite direction, that is; a signal on a separate communication line All communication data streams are transmitted in two opposite directions (half-duplex working mode).
MODBUS protocol only allows communication between the host (PC, PLC, etc.) and the terminal device, but does not allow data exchange between independent terminal devices, so that each terminal device will not occupy the communication line when they are initialized, and the response arrives The query signal of this machine.
[Synchro Intelligent 舜高智能]
■ 功能特点
仪表可监测下列电能质量参数：
- 畸变率与谐波含量
可测量三相电压、电流的谐波畸变率；2-31th 谐波含量（通过通信读取）。
- 波峰系数
波峰系数是电压的峰值与平均值的比值。
- 电流K 系数
K 系数是描述供电给非线性负载变压器额外发热的参数，反映变压器承受谐波时所额外温升的能力。
- 不平衡度
指三相电力系统中三相不平衡程度。用电压、电流负序基波分量或零序基波分量与正序基波分量的方均根值的百分比表示。根据对称分量法，三相系统中的电量可分解为正序分量、负序分量和零序分量三个对称分量；本仪表采用负序基波分量与正序基波分量均方根值的百分比。
Ein Multifunktions-Leistungsmesser mit programmierbaren Funktionen für Messung, Anzeige, digitale Kommunikation und Energieimpulsausgabe. Es kann Strommessungen, Energiemessungen, Datenanzeigen, -erfassungen und -übertragungen durchführen und ist in Umspannwerken weit verbreitet. Automatisierung, Automatisierung der Energieverteilung, intelligente Gebäude, Energiemessung, -verwaltung und -bewertung innerhalb des Unternehmens. Die Messgenauigkeit ist erstklassig, da die LED-Anzeige vor Ort und die digitale RS-485-Fernschnittstellenkommunikation unter Verwendung des MODBUS-RTU-Kommunikationsprotokolls realisiert werden.
