ComAp Inteli Mains NTC BaseBox User Manual

Communication Guide, ©ComAp – March 2014 118
IGS-NT Communication Guide 03-2014.pdf
Check field calculation
The check field allows the receiver to check the validity of the message. The check field value is the
Cyclical Redundancy Check (CRC) based on the polynomial x
16
+x
15
+x
2
+1. CRC is counted from all
message bytes preceding the check field. The algorithm of CRC calculation is introduced below on an
example of a C language function.
unsigned short count_CRC(unsigned char *addr, int num)
{
unsigned short CRC = 0xFFFF;
int i;
while (num--)
{
CRC ^= *addr++;
for (i = 0; i < 8; i++)
{
if (CRC & 1)
{
CRC >>= 1;
CRC ^= 0xA001;
}
else
{
CRC >>= 1;
}
}
}
return CRC;
}
Online CRC calculator: http://www.lammertbies.nl/comm/info/crc-
calculation.html
Controllers use the CRC-16 (Modbus). Data in examples in this manual are in
HEX format.
How get numbers of ModBus communication
objects
Communication objects can be
spitted into two groups:
1. Communication objects
dependent on the application
type (SSB, SPM, SPtM, MEXT,
MINT, …).
2. Communication objects
independent on the application
type.
Use GenConfig menu command
File –> Generate Cfg Image –>

ComAp Inteli Mains NTC BaseBox Specifications

General

Operating temperature	-20 to +70 °C
Communication	RS232, RS485, CAN
Protection	IP20
Communication Ports	RS232, RS485, CAN
Supply voltage	8-36 V DC
Inputs/Outputs	8 binary inputs, 8 binary outputs, 4 analog inputs
Operating Temperature Range	-20 to +70 °C
Storage Temperature Range	-30 to +80 °C
Humidity	95% non-condensing

Summary

Controller Communication Capabilities

IG/IS/IM-NTC-BB Controller Details

Covers communications, terminals, modules, and jumpers for this series.

IG/IM-NT-BB Controller Details

Details communications, terminals, modules, and jumpers for this series.

Other Controller Series Capabilities

Covers IG-NT, IG-NTC, IS-NT-BB, IM-NT communications and terminals.

Monitoring Local on Site - ComAp SW

Direct PC Connection to Single Gen-set

Explains RS232, USB, RS485, and Ethernet connections for single gen-sets.

Direct PC Connection to Multiple Gen-sets

Details RS485, I-LB+, IB-NT, and Ethernet connections for multiple gen-sets.

Monitoring Local on Site - MODBUS

Modbus Single Gen-set Connections

Details RS232, RS485, and Ethernet Modbus connections for single units.

Modbus Multiple Gen-set Connections

Covers RS485, I-LB+, and Ethernet Modbus connections for multiple units.

Remote Monitoring

Internet Connection Methods

Web-based Monitoring

Modem Connection

Modem Connection to Single Gen-set

Modem Connection to Multiple Gen-sets

Peripheral Modules

Controller Displays

Communication Extension Modules

Modbus Protocol Implementation

Modbus Connection Steps and Setpoints

Outlines connection types, setpoints, and communication steps for Modbus.

Modbus Communication via Different Interfaces

Modbus Communication Details

Modbus Data Reading Procedures

Modbus Data Writing Procedures

Modbus Protocol Description and Examples

Modbus Protocol Overview

Modbus Communication Examples

Alarm and History Management

Controller Commands

IGS-NT Controller Commands

IM-NT Controller Commands