A-B BAS-T Module and Development Software Overview

Overview

The module and the development software provide the following benefits.

• Easy data collection from user devices

• Integrated program debugging environment

• Operator interface capabilities

• Flexible program and data storage options

• High-level math

• Clock/calendar

• High-level programming environment

• Extensive online help system

• Easy access to editor functions through user interface

• Advanced text editor windows

TIP

The 1746-BAS-T module is a higher-speed version of 

the 1746-BAS module with identical hardware 

features. The modules can be interchanged, except 

that the 1746-BAS-T module uses different (optional) 

memory modules. Due to the high speed of the 

1746-BAS-T module, existing programs written for 

the 1746-BAS module may require adjustment for 

identical operation using the faster 1746-BAS-T module.

BASIC and BASIC-T Modules

The modules are single-slot modules that reside in a SLC 500 fixed or modular controller chassis.

Use the module as:

• a foreign device interface.

• an operator interface.

Hardware Features

The module provides the following hardware features.

• 24 KB of battery backed RAM for storage of user programs and data

• Capacitive backup of RAM during battery change

• Socket for a standard 1747-M1, M2, M3, or M4 memory module 

(1746-BAS module) for nonvolatile storage of user programs

• Socket for a 1771-DBMEM1 or -DBMEM2 memory module 

(1746-BAS-T module) for nonvolatile storage of user programs

• Battery-backed, 24-hour clock/calendar

• Free-running clock with 5 ms resolution

• Two isolated 9-pin D-shell serial ports (PRT1 and PRT2) that 

provide RS-232/423, RS-422, and RS-485 communication with I/O devices

• One PRT2 port provides DF1 full-duplex or half-duplex slave 

protocol for SCADA applications

• One RJ-45 port (DH485) that provides communication over the DH485 network

• Multiple LED indicators for operator interface

• SLC 500 backplane interface

Software Features

The module provides the following software features.

• BASIC programming with the Intel BASIC-52 language and enhancements

• SLC 500 backplane data read and write support including image 

table transfers and M0 and M1 file transfers

• Execution of programs from memory modules

• String manipulation support

• DH485 network support

• DF1 protocol support

• Full set of trigonometric function instructions

• Floating point calculations and conversion

• Extensive call libraries

Module Communication Ports

There are three communication ports on the front of the module. The 

location, name, and pin numbers of these ports are listed on the 

inside of the module door. 

They are:

• PRT1 - Used to interface the module with user devices. This port 

is a serial port that accommodates RS-232/423, RS-422, and 

RS-485 communication modes. Port PRT1 is capable of operating 

full-duplex at 300, 600, 1200, 2400, 4800, 9600, and 19200 Kbps. 

The default settings are 1200 Kbps, RS-232/423 communications.

• PRT2 - Used to interface the module with user devices or a 

modem using DF1 protocol. This port is a serial port that 

accommodates RS-232/423, RS-422, and RS-485 communication 

modes. Port PRT2 is capable of operating full-duplex at 300, 600, 

1200, 2400, 4800, 9600, and 19200 Kbps.

• DH485 - Used to interface the module with the DH485 network. 

This port is not isolated and cannot directly drive the DH485 network. 

You must use a 1747-AIC link coupler to link port DH485 with the DH485 network.