5701系列控制系统是System 57系列的一部分，用于监控现场安装的工业气体探测器。校长
该系统的特点是:
*使用3U卡格式，在标准19“机框中提供多达16个通道的气体检测。
*使用3U卡格式，在半19“机框中提供多达8个通道的气体检测。
*机架可用于前面和后面的访问现场布线。
*简单的现场连接电线高达2.5mm2
*高完整性系统的单通道操作模式。
*通道控制卡可拆卸，不干扰其他布线。
*催化桥或4 – 20mA输入。
*可选报警转换继电器输出。
*多报警模式主，分区和投票报警。
*上升，下降，STEL和LTEL / RATE报警输出。
*更新单个或多通道报警。
*远程抑制和复位输入。
*继电器输出的开关接通和/或开关断开的时间延迟。
*可选0 – 20mA或4 – 20mA隔离监视器输出。
*使用专用工程卡易于校准和操作。
* EMC兼容。
*通过工程卡提供的选项:
*主告警更新。
*事件打印机。
*采用Modbus协议进行串行通信。

该系统由单独的1英寸(2.54厘米)宽的卡安装在一个刚性定制机架上，旨在适应欧洲机架机柜。两种机架宽度可供选择:
a. 19英寸，17个卡槽，最多可容纳16个通道控制卡和一个工程卡。
b.半19英寸，9个卡槽，最多可容纳8个通道控制卡和1个工程卡。
每个子机架包含一个工程卡和一个直流输入卡组成机架系统
该系统旨在满足不同的客户接线配置，为了实现这一目标，控制功能从继电器和现场接线连接中分离出来。因此，单个气体检测通道包括:
a.传感器驱动模块
为了实现与一系列不同输入和传感器类型的兼容性，控制传感器所需的电路被安置在一个独立的插入式传感器驱动模块上。这些模块直接插入通道控制卡，并在工厂安装。有两个不同的模块，一个用于催化输入，一个用于4 – 20mA输入。
b.单通道控制卡
每个单通道控制卡独立工作，并包含所有必要的电子电路，以提供传感器驱动，报警检测和气体液位显示该通道的气体检测。
c.现场接口或中继卡
现场接口/继电器卡提供控制卡和各自的现场连接气体传感器之间的接口连接。此外，中继卡提供报警输出到现场连接。

The 5701 Series Control System is part of the System 57 family and is designed to monitor field mounted industrial gas detectors. The principal
features of the system are:
* Provides up to 16 channels of gas detection in a standard 19” subrack using a 3U card format.
* Provides up to eight channels of gas detection in a half 19” subrack using a 3U card format.
* Racking available for both front and rear access field wiring.
* Simple field connections for wire up to 2.5mm2
* Single channel mode of operation for high integrity systems.
* Channel Control Cards removable without disturbing other wiring.
* Catalytic bridge or 4 – 20mA input.
* Optional alarm change-over relay outputs.
* Multi-alarm mode for master, zoned and voted alarms.
* Rising, falling, STEL and LTEL / RATE alarm outputs.
* Update alarm on individual or multi channel alarms.
* Remote inhibit and reset inputs.
* Time delay on switch on and/or switch off of relay outputs.
* Optional 0 – 20mA or 4 – 20mA isolated monitor output.
* Easy to calibrate and operate using a dedicated Engineering card.
* EMC compliant.
* Options provided via Engineering Card:
* Master Alarm Update.
* Event Printers.
* Serial communication using Modbus protocol.

The system consists of individual 1” (2.54cm) wide cards fitted to a rigid custom rack designed to fit Euro rack cabinets. Two rack widths are available:
a. 19 inch with 17 card slots to house up to 16 Channel Control Cards and an Engineering Card.
b. Half 19 inch with nine card slots to house up to eight Channel Control Cards and an Engineering Card.
Each sub-rack contains an Engineering Card and a DC Input Card to make up the rack system
The system is designed to meet the differing customer wiring configurations and to achieve this the control functions are split away from the relays and field wiring connections. A single channel of gas detection therefore consists of:
a. Sensor Drive Module
In order to achieve compatibility with a range of different inputs and sensor types, the circuitry necessary to control the sensor is housed on an independent plug-in Sensor Drive Module. These modules plug directly into a Channel Control Card and are factory fitted. There are two different modules, one for catalytic inputs and one for 4 – 20mA inputs.
b. Single Channel Control Card
Each Single Channel Control Card functions independently and contains all the necessary electronic circuitry to provide the sensor drive, alarm detection and gas level display for that channel of gas detection.
c. Field Interface or Relay Card
The Field Interface/Relay Cards provide the interface connections between the Control Cards and their respective field connected gas sensor. In addition, Relay Cards provide alarm outputs to the field connections.