enraf CIU Prime 880 - User Manual

The CIU Prime type 880 (CIU858 emulation) is an interface unit designed to bridge field instrumentation with higher-level inventory systems. It serves as a successor to the CIU type 858, offering compatibility with existing CIU858 protocols while providing enhanced capabilities.

Function Description

The primary function of the CIU Prime type 880 is to act as a communication interface between various field instruments and inventory management systems. It automatically polls connected gauges, stores the collected information in an internal database, and makes this data available to host systems. The unit supports emulation of the CIU858 protocol, primarily on host port 2, to ensure compatibility with legacy systems.

When the CIU Prime receives data request records from a host, it processes them as follows:

Known instrument, data available: An answer is generated by the CIU Prime using information from its database.
Known instrument, no data available: The received record is transmitted to the addressed instrument (field line), and the instrument's reply is then forwarded to the host.
Unknown instrument: The received record is transmitted to all field ports, and the first instrument reply received is forwarded to the host.

The device also handles time-out records from the CIU (indicating no gauge answer) by retrying data retrieval up to three times before signaling an alarm.

Important Technical Specifications

Communication Parameters: The CIU Prime type 880 supports asynchronous RS232-C / RS485 communication, non-isolated, DTE-side, exclusively on host port 2.

Baudrate: 1200, 2400, 4800, 9600, 19200 baud.
Parity: Odd or Even.
Start bit: 1.
Data bits: 7, LSB first (7 bits ASCII character).
Stop bit(s): 1.
TX/RX mode: Half Duplex.
Turn around delay: Adjustable in milliseconds.

CIU (858) Address: The CIU (858) address depends on the type of field port:

EN-bus (direct Enraf instruments): The CIU858 emulation address is the last decade of the decimal representation of the RTU address for host port 2. For example, if the RTU address is 123, the CIU858 emulation address is 3.
RS-232c (connected CIU858): The CIU858 emulation address is the address of the connected CIU858. It is important that the address of the connected CIU858 is not identical to the last decade of the decimal representation of the RTU address of host port 2 (e.g., if RTU address is 30, CIU858 address cannot be 0).

Physical Interfaces:

Field Ports: Up to four input boards can be installed. These can interface to the EN-bus (BPM Bi-Phase Mark). By replacing input boards with RS-232C/RS485 input boards, the CIU Prime can interface with 858 CIUs.
Host Ports: Two fixed RS-232C/RS485 output boards are available for interfacing with CIU Plus, PLC, ENSITE, and other systems.

Usage Features

Protocol: The CIU Prime type 880 utilizes a request/reply communication protocol based on command and answer records.

Command Records:
- Individual CIU Command Record: Executed by the addressed CIU Prime, which then sends an answer record. This includes commands to retrieve the CIU-GPU version or send an identify record.
- Instrument Individual Command Record: Passed on to connected field instruments (without the CIU address). Supports various instrument types (e.g., 811, 854, 873 with GPU protocol; 813 MGT; 875 Field Interface Unit; 874 Analog Input Module).
- Instrument Group Command Record: Transmitted to all connected instruments (without the CIU address). The CIU responds with a time-out record as an acknowledgment.
Answer Records:
- CIU Answer Records: Transmitted to the computer system after receiving a CIU individual command record.
- X-record (Identification Record): Implemented for compatibility, providing a default answer.
- Time-out Record: Transmitted after an instrument group command, or if a field instrument malfunctions or is unresponsive.
- Instrument Answer Records: Passed to the computer system after a correctly received instrument individual command, with the CIU adding its own address to the record.

Data Structure: All records consist of a data field enclosed in an envelope: STX DATAFIELD ETX BCC.

STX (Start of TeXt): ASCII value 002.
ETX (End of Text): ASCII value 003.
BCC (Block Check Character): Used for error detection.

BCC Calculation: The Block Check Character (BCC) is calculated as the binary sum (exclusive OR) of the seven individual data bits of all transmitted bytes, excluding STX but including ETX, according to ANSI standard X3.28 - 1976. The BCC can be any of the 128 code combinations and should be interpreted as the BCC, not another character.

ACK Characters: The CIU transmits ACK (ACKnowledgement) characters approximately every 50 milliseconds when it is busy processing a command or engaged in field communication. This indicates that the CIU intends to send an answer record as soon as possible, allowing the host system to reset its time-out period. A new command is not accepted while ACK characters are being sent.

Maintenance Features

The CIU Prime type 880 is configurable and programmable. For detailed configuration and programming instructions, users should refer to the CIU Prime's configuration manual. The CIU858 emulation mode must be explicitly enabled via the Ensite Pro configuration program.

The manual emphasizes the importance of adhering to prescribed procedures and warns against executing unprescribed activities to prevent personal injury or equipment damage. It also advises users to retain their proof of purchase for warranty purposes.

enraf CIU Prime 880 Specifications

General

Brand	enraf
Model	CIU Prime 880
Category	Cell Phone
Language	English

enraf CIU Prime 880 - User Manual

Table of Contents

Summary

Preface

Safety and Prevention of Damage

Legal Aspects

Additional Information

Introduction

CIU Prime

Field Ports

Host Ports

Automatic Polling

Communication Parameters

Transmission Mode

Baudrate

Parity

Start Bit

Data Bits

Stop Bit(s)

TX;RX Mode

Turn Around Delay

CIU (858) Address

Communication Procedure

Command Records

Record Structure

General Form

CIU Individual Command Record

Instrument Individual Command Record

Instrument Group Command Record

CIU Answer Records

X-record (Identification Record)

Time-out Record

Instrument Answer Records

BCC Calculation

ACK Characters

Appendix A: Related Documents

Instruction Manual 880 CIU Prime

Instruction Manual 880 CIU+

Instruction Manual Modbus Protocol

Instruction Manual ENSITE Pro - 880 CIU Prime

Instruction Manual ENSITE Pro - 880 CIU+

Instruction Manual ENSITE - ENTIS Pro under Windows NT