Analog Inputs
Any one of the sixteen 16-bit analog inputs may be independently configured to read voltage, 4-20 mA current loops or thermocouples. The 2608 has built-in 500 ohm resistors for the current loops.
All measurements are made differentially to reduce common mode noise. All field wiring is connected directly to the 2608 via removable terminal blocks as shown in the photo. This minimizes downtime should it become necessary to replace a 2608 module. It also eliminates the need for separate terminal block assemblies.
Peripheral Modules
| Model 2601 | Communication module | | Model 2608-0 | 16 analog and TC inputs (16 bit) | | Model 2608-4 | 16 analog and TC inputs (16 bit), 4 analog outputs (16 bit) | | Model 2608-8 | 16 analog and TC inputs (16 bit), 8 analog outputs (16 bit) | | Model 2610 | 48 digital I/O, 5VDC to 24VDC | | Model 2620 | 4 encoder/counter/frequency interfaces (32 bit) | | Model 2650 | 8 relay outputs, 0V to 240V @ 10A | | Model 2652 | SSR I/O Module (Supports 8 SSRs) | | Model 2653 | SSR I/O Module (Supports 16 SSRs) | | Model 204 | Power supply, 24 VDC @ 5A | |
Auto standardize
The 2608 has automatic standardization circuitry that periodically measures on-boards reference standards to update the gain and offset of the analog section. Eight temperature sensors, four on each side of the module, are also sampled. Subsequent readings use the newest computed gain, offset and cold junction temperature. Factory calibration constants are stored in non volatile memory so that 2608’s can be replaced without requiring field calibration.
Filtering
A 16-bit A/D digitizes all analog inputs and internal references at two milliseconds intervals. Each input is measured four times in rapid succession and the averaged results are stored in on-board memory. Since this process is repeated every two milliseconds, the effective A/D sampling rate is 500 Hz per channel. A more heavily filtered result is also available from averaging readings over 16 milliseconds. This has the effect of reducing 60 Hz line noise.A 50 Hz filter may also be chosen. Thermocouple and internal voltage references use this line filter. A jumper selectable RC filter is also available for thermocouples.
Analog Outputs
The 2608 is available without analog outputs. Each D/A converters produce +/- 10 VDC with a resolution of 15-bits. All channels default to zero volts upon reset or power-up. Each D/A has a 5-pin connector for external loads. Pin 3 is a remote sense line used to compensate line losses. Pin 5 is an optional power output line for powering external sensors with 24 or 10 VDC. An on-board DC/DC converter produces all the required voltages from the 24 VDC supplied from the 2601 communication module.
Software & Manuals
2600 Hardware Manual >> Released 2/23/06
2600 Programming Guide >> Released 2/23/06
2600 Software Development Kit >> Released 2/23/06
2608 LabView Software >> 3/8/06
LabVIEW Software Interface (click for image) Feature Article: The future of Industrial I/O |
