Resumen
Description of modem
The CS-SRM Short-Range Modem package is ideal for communication between a remote Campbell Scientific datalogger and a computer with an RS232 port. The CS-SRM ensures integrity of data transmission using unconditioned 4-core cable at data rates up to 19200 baud. The modem operates over distances up to 12km (7.44 miles) depending on wire gauge and data rate.
Function
When used with a PC running Campbell Scientific software, the CS-SRM package allows data retrieval, uploading and downloading of datalogger programs and remote monitoring.
Operation
The CS-SRM can operate without a mains supply; ultra low power consumption allows it to be driven from the standard RS232/V24 data and control signal voltages at the PC and from the CSI/O port on the logger.
Transmission levels are chosen to minimise cross-talk onto adjacent circuits within the same
cable. Data is transmitted and received at a balanced impedance, ensuring excellent immunity to circuit noise.
The model 5A modem is not BABT approved. However a fully BABT-approved model for use in the UK on leased lines (such as EPS8) is available to special order.
Imágenes
Especificaciones
Communication
Data Rate: Up to 19200 baud with Campbell Scientific dataloggers
Transmission Range: Up to 12km
Transmission Line: 4-wire unconditioned cable (two twisted pairs)
Transmission Mode: Asynchronous, full duplex
Connections
Terminal Interface: RS232, 25-way D-type female connector
Line Interface: 5-way (four wires and ground) via terminal block
Power Requirements (with SC932C): less than 2.5mA quiescent, 10-15mA active
Protection from Electrical Transients
The RAD-SRM is coupled to the telephone cable through isolation transformers rated at over 1500V RMS. Surge protectors (model RAD-SP) are included for additional protection where the lines run outside.
NOTE: Campbell Scientific will not accept any warranty claims where damage to the RAD-SRM has occurred because the recommended surge protectors were not used.
Customer-supplied surge protectors may be needed on the AC supply to protect the PC. Call for further information.
Operation Details
The modem will operate fully even if only the Transmit Data line is connected — i.e. without the terminal sending Request to Send or Data Terminal Ready signals. Both positive and negative signals are generated in compliance with EIA RS232C/CCITT V24 standards irrespective of the state of the Transmit Data line.
Physical
Operating Temperature: 0°C to +50°C
Humidity: Up to 90%, non-condensing
Size: 52mm x 53mm x 18mm
Weight: 38g