5701系列控制系統是System 57系列的一部分，用于監控現場安裝的工業氣體探測器。校長
該系統的特點是:
*使用3U卡格式，在標準19“機框中提供多達16個通道的氣體檢測。
*使用3U卡格式，在半19“機框中提供多達8個通道的氣體檢測。
*機架可用于前面和后面的訪問現場布線。
*簡單的現場連接電線高達2.5mm2
*高完整性系統的單通道操作模式。
*通道控制卡可拆卸，不干擾其他布線。
*催化橋或4 – 20mA輸入。
*可選報警轉換繼電器輸出。
*多報警模式主，分區和投票報警。
*上升，下降，STEL和LTEL / RATE報警輸出。
*更新單個或多通道報警。
*遠程抑制和復位輸入。
*繼電器輸出的開關接通和/或開關斷開的時間延遲。
*可選0 – 20mA或4 – 20mA隔離監視器輸出。
*使用專用工程卡易于校準和操作。
* EMC兼容。
*通過工程卡提供的選項:
*主告警更新。
*事件打印機。
*采用Modbus協議進行串行通信。

該系統由單獨的1英寸(2.54厘米)寬的卡安裝在一個剛性定制機架上，旨在適應歐洲機架機柜。兩種機架寬度可供選擇:
a. 19英寸，17個卡槽，最多可容納16個通道控制卡和一個工程卡。
b.半19英寸，9個卡槽，最多可容納8個通道控制卡和1個工程卡。
每個子機架包含一個工程卡和一個直流輸入卡組成機架系統
該系統旨在滿足不同的客戶接線配置，為了實現這一目標，控制功能從繼電器和現場接線連接中分離出來。因此，單個氣體檢測通道包括:
a.傳感器驅動模塊
為了實現與一系列不同輸入和傳感器類型的兼容性，控制傳感器所需的電路被安置在一個獨立的插入式傳感器驅動模塊上。這些模塊直接插入通道控制卡，并在工廠安裝。有兩個不同的模塊，一個用于催化輸入，一個用于4 – 20mA輸入。
b.單通道控制卡
每個單通道控制卡獨立工作，并包含所有必要的電子電路，以提供傳感器驅動，報警檢測和氣體液位顯示該通道的氣體檢測。
c.現場接口或中繼卡
現場接口/繼電器卡提供控制卡和各自的現場連接氣體傳感器之間的接口連接。此外，中繼卡提供報警輸出到現場連接。

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.