一、概述

     ZXD-A转速信号测控仪可完成水轮机发电机组的转速百分比或频率测量，其输入信号可取主机残电压（电流互感器边）、永磁机电压，输出采用七路继电器控制和一路12位D/A转换输出模拟量。机组的转速百分比和频率由四位LED数码管显示，七路继电器的工作状态由七只LED发光二极管分别指示。本仪表除可带4—20mA ,1—5V ，0—20mA， 0—5V等标准直流信号输出外，还可带RS—485，RS—232C，RS—422A等标准串行口输出，输出采用光电隔离，使得仪表可以与计算机直接接口。

本仪表关键元器件采用美国ATMEL公司、 MAXIM公司、TI公司的产品。仪表掉电采用E²PROM数据保护，初始设置的所有参数及工作状态不会因突然停电而丢失，可永久保存；输入、输出采用光电隔离技术，使得仪表完全满足电厂安全、及时、稳定、可靠的工作要求。

二、主要技术参数

1、输入信号

1）发电机残压；2）发电机PT频率

2、输入电压范围：发电机残压或PT信号0.3-250VAC

3、测量精度： 0.1级

4、测频范围：频率0.02 –99.99 HZ、 转速百分比 2%-200%

5、输出信号

1）7路继电器常开触点输出

2）模拟信号输出： 4—20mA (对应于机组转速的0%-200%)

3) RS485串行通信接口输出：标准MODBUS通信协议

6、工作环境： 温度-10—50 ℃ ，相对湿度≤85% 无腐蚀性气体及导电、易爆、尘埃等场所。

7、外型尺寸 ：  宽×高×深 = 160 ×80×160 mm

8、电源 ：开关电源，交流185——250V或直流75——300V

E． Outline

 ZXDThe rotational speed signal observation meter may complete hydraulic turbine power set the rotational speed percentage or the frequency measurement, its input signal may take the main engine remnant voltage (nearby current transformer), permanent magnetism machine voltage, the output uses seven group black-white controls and a group 12 D/A transformation output simulation quantity. Unit's rotational speed percentage and the frequency demonstrated by four LED nixietubes that seven group relay's active statuses instructed separately by seven LED light emitter diode. This measuring appliance besides may bring 4-20mA, 1-5V, 0-20mA, standard cocurrent signal outputs and so on 0-5V, but may also bring RS-485, RS-232C, RS-422A and so on standard serial port output, the output uses the electro-optical isolation, causes the measuring appliance to be possible with the computer direct connection

This measuring appliance essential primary device uses American ATMEL Corporation, MAXIM Corporation, the TI Corporation's product. The measuring appliance power failure uses the E2PROM data protection, because initial establishment's all parameters and the active status will not cut power suddenly lose, but permanent preservation; The input, the output use the electro-optical isolation technology, causes the measuring appliance to satisfy the power plant safely completely, prompt, stable, the reliable work requirement

二、Major technique parameter

1、Input signal :

1）Generator remnant pressure ；2）Generator PT frequency

2、Input voltage scope ：Generator remnant pressure or PT signal 0.3-250VAC

3、Measuring accuracy:0.1 level

4、Frequency measurement scope: Frequency 0.02 - 99.99 HZ, rotational speed percentage 2%-200%

5、output signal

 1) 7 group relay normally opened contact output

2) simulated signal output: 4-20mA (corresponds to unit rotational speed 0%-200%)

3) RS485 serial communication connection output: Standard MODBUS communication protocol

6、Working conditions: Temperature - 10-50 ℃, relative humidity ≤85% non-corrosiveness gas and electric conduction, explosive, places and so on dust.

7、Outlook size: Wide * high * deep = 160 ×80×160 mm

8、Power source: The switching power supply, exchanges 185--250V or directs current 75--300V