Siemens SIREC P/PA Process Instrumentation Point Recorder 7ND3021-1AA11-1NA1

The SIREC P/PA series is a family of industrial chart recorders from Siemens. The model 7ND3021-1AA11-1NA1 is a point recorder capable of recording up to 12 analog inputs with user-selectable colors and scales. It accepts a wide range of signals: thermocouples (J, K, T, R, S, B), RTDs (Pt100, Ni100), DC voltage (±1V to ±200V) and DC current (0/4–20 mA). The recorder uses a thermal array printhead on Z-fold paper, producing clear traces and alphanumeric annotation. It is used for long-term monitoring of process variables in chemical, power, and pharmaceutical plants.

Input Specifications

• Number of Inputs: Up to 12 universal analog inputs (6 on base unit, expandable)

• Sampling Rate: 100 ms per channel

• Accuracy: ±0.1% of reading ±1 digit (thermocouple), ±0.05% for DC signals

• Isolation: 1500 VAC between channels and power

• Common Mode Rejection: >120 dB at 50/60 Hz

Recording and Display

The thermal printer prints chart speed from 1 mm/h to 1200 mm/h. Paper width is 100 mm (foldable stack, 20 m length). The recorder also has a backlit LCD (240×128 pixels) for trend display and configuration. Recording modes include continuous trace, multipoint (dots for each channel), or a combination. Each channel can have its own color (six colors available via multicolor ribbon).

Communication and Alarms

The unit features an RS-232/485 port with Modbus RTU protocol for remote data retrieval. Four alarm relays (SPDT, 250 VAC 5A) are standard; additional relays are optional. The recorder logs alarms with time stamp and can trigger printout of alarm messages. Internal non-volatile memory stores configuration and up to 512 alarm events.

Physical and Environmental

Dimensions: 288 mm × 144 mm × 320 mm (H × W × D), 1/4 DIN panel mount. Weight: 4.5 kg. Power supply: 100–240 VAC, 50/60 Hz, 35 VA. Operating temperature: 0–50°C; storage: -20–60°C; humidity: 10–90% non-condensing. Protection: front panel IP54 (with gasket), rear IP20. The recorder is CE, UL, and CSA certified.

Applications and Installation

Commonly used in environmental chambers, boiler monitoring, and batch process recording. The 7ND3021-1AA11-1NA1 replaces earlier SIREC L and P series recorders. For paper and ribbon supplies, order Siemens part numbers: 7NG2000-1A (paper), 7NG2000-1R (ribbon). The recorder can be configured via front panel keys or using SIREC service software (free download).