● Converts simple ASCII commands into Modbus RTU messages. Relieves user from having to generate and check RTU packets. ● Expanded Modbus RTU Command Set now includes Floating Point commands. Controls a wider range of Modbus devices. ● Provides both single ended RS-232 and balanced RS-422/RS-485 serial signals. Connects to single and multiple Modbus devices. ● GPIB Interface is IEEE-488.2 Compliant. Meets latest GPIB Standards. ● Saves GPIB address, serial settings and user IDN message in non-volatile memory. Personalize the 4809 as part of your system. ● Diagnostic LEDs show address and status. Visual indication of operation and test status. ● Operates on +5 to 15 Volt power. Uses existing power supplies in most cases.
ICS Modbus Interface Board 4809A GPIB<->Modbus Interface is an IEEE 488.2/GPIB to Serial Interface that easily adapts Modbus slave devices to the GPIB or HP-IB bus. The 4809A lets the user send simple read-write messages on the GPIB bus to control and query slave Modbus devices. The ICS Modbus Interface Board 4809A does all of the Modbus packet formatting and handles the response packets. The 4809A has both RS-232 and RS-485 interfaces so it can be connected directly to a single Modbus slave device or it can be connected to multiple Modbus devices via an RS-485 network. The 4809A firmware has an expanded Modbus command set and now includes 32-bit floating point commands so it can control newer temperature controllers. The ICS Modbus Interface Board 4809A is fully backward compatible with the earlier 4809.
The 4899A conforms to the SCPI 1994.0 Specification and uses SCPI commands to set:
GPIB Bus Address External GPIB Address Enable Baud rate select Data bits 7 or 8 Stop bits 1 or 2 Parity Odd, Even or None RS485 Half-Duplex operation Talk Format HEXlist or ASCII
Interface Specifications
Full duplex serial interface with single ended RS-232 and differential RS-422 (RS-485) signals. Signal selection made by jumpers on the 4899A. RS-485 half duplex operation enabled with a SCPI command.
RS-232 Signals
TxD, RxD, RTS, CTS, DSR and DTR
RS-422 Signals
Tx and Rx pairs
Baud Rates
300, 600, 1.2K, 2.4K, 4.8K, 9.6K, 19.2K and 38.4K baud
Data Bits
7 or 8 bits
Parity
Odd, Even or None
Stop Bits
1 or 2
Modbus Commands
Modbus commands accept ASCII decimal values or HEX values starting with #h. Code is the Modbus RTU command code produced by the 4899A. Integer and register values from 0 to 65,535. Floating Point per IEEE-754.
Compatible Controllers
The following is a partial list of compatible Modbus RTU Slave Controllers:
Watlow F4, 96, SD and EZ Zone series
Cincinnati SubZero EZT550
Controls and Indicators
Indicators
PWR
On when power applied
RDY
On when passed self test
TALK
On when addressed to talk
LSTN
On when addressed to listen
SRQ
On when asserting SRQ
ERR
On when ESR error bits set
Grootte
139.7 x 114.3 x 12.7mm (L x W x H)
Connectors and Headers
Three flat ribbon headers
GPIB
24-pin 3M 2524 male connector mates to panel mounted GPIB connector.
GPIB/Addr
26-pin 3M 2526 male connector mates to ICS GPIB/Connector Switch Assemblies.
Serial
26-pin 3M 2526 male connector mates to a DB-25 pin connector.
