ICS Modbus Interface Board 4829A
GPIB <-> RS-422/RS-485 Modbus Interface Board
● Converts simple ASCII commands into Modbus RTU messages. Relieve user from having to generate and check RTU packets.
● Expanded Modbus RTU Command Set includes Floating Point commands. Controls a wider range of Modbus devices.
● Provides GPIB and RS-232 to RS-422/RS-485 data paths for Modbus RTU devices. Use GPIB or RS-232 to control RS-485 Modbus devices.
● IEEE-488.2 Compliant. Meets latest GPIB Standards.
● Saves GPIB address, serial settings and user IDN message in non-volatile memory. Personalize the 4829A as part of your system.
● Runs on 5 to 15 VDC. Uses available DC power.
● Mounts directly to host chassis' rear panel. Easy installation eliminates extra cables and reduces cost.
ICS Modbus 4829A GPIB<->Modbus Interface Board is an IEEE 488.2/GPIB to Serial Interface that adapts Modbus RTU slave devices with RS-422/S-485 interfaces to the GPIB bus and to RS-232 serial links. The ICS Modbus Interface Board 4829A lets the user send simple read-write messages on the GPIB bus to control and query slave Modbus RTU devices. The 4829A does all of the Modbus packet formatting and handles the response packets. The 4829A also provides all of the required IEEE-488.2 functions and an expanded IEEE-488.2 Status Reporting Structure to report Modbus communication errors. The ICS Modbus Interface Board4829A also provides a RS-232 to RS-422/RS-485 converter function so that a RS-232 data source can control RS-422/RS-485 Modbus slave devices with the serial Modbus RTU protocol. Typical applications are adding a GPIB interface to a temperature chamber or system using a Watlow EZ Zone or other Modbus RTU slave devices.
| IEEE 488 Bus Interface |
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| Address Capability | Primary addresses 0 ~ 30. Address set by GPIB bus command. Address displayed on LED indicators at power turn-on. | ||||||
| SRQ Generation | SRQs are generated per the IEEE-488.2 specification when the unit is not addressed to talk and an enabled bit in the ESR, Questionable or Conditional register becomes set. ESR bits are: Modbus Error Register set Serial Buffer full Command error Serial error Execution error Query error Power on |
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| Buffers |
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| 488.2 Common Commands | *CLS, *ESE, *ESE?, *ESR?, *IDN?, *OPC, *OPC?, *RST, *SAV, *SRE, *SRE?, *STB, *TST? and *WAI. |
Rear panel serial signals conform to EIA Specifications for RS-232 signals. J2 is a DTE type interface with DR, CTR and RTS signals pulled to +V.
| Signals | TXD, RXD, GND |
| Baud Rates | 300 ~ 57.6 Kbaud |
| Data Bits | 7 or 8 bits |
| Parity | Odd, Even or None |
| Stop Bits | 1 or 2 |
Internal serial signals are 4-wire or 2-wire RS-485 signals capable of driving 32 RS-422/RS-485 loads. Rx Differential receiver includes a termination network to hold the signals in a mark state when they are not being driven. 4-wire or 2-wire signal selection set by on card jumpers. Signal transmitter can be set for full or half duplex operation. The baud rate and data character format settings applies to both serial connectors.
| Indicators | |
| Six on board LEDs show self test diagnostics, GPIB address and status. | |
| PWR | On when power applied |
| RDY | On when passed self test |
| MTA | On when talk address recognized |
| MLA | On when listen address recognized |
| SRQ | On when SRQ generated |
| ERR | On when ESR register bit set |
| GPIB | 24-pin IEEE-488 connector with metric lock studs. |
| Ext. Serial | 9-pin DE shell male connector with 4-40 lock studs. |
| Int. Serial | 9-pin DE shell female connector with 4-40 lock studs. |
| Operation Temperature | -10 °C ~ +70 °C |
| Storage Temperature | -40 °C ~ +85 °C |
| Humidity | 0-90% RH without condensation |
| Construction | Four layer fire-resistant PCB. Connector shells and mounting blocks are connected to chassis ground. |
Configuration Disk with sample programs