In the fields of digital video surveillance (DVR), factory automation testing, medical imaging, and scientific research instruments, synchronously collecting multiple standard composite video (PAL/NTSC) signals to a PC for real-time processing is the core challenge of system design. The RTV series frame grabber launched by ADLINK covers various forms such as PCIe-RTV24 (PCI Express x1), PCI-RTV24 (traditional PCI), cRTV-24 (3U CompactPCI), cRTV-44 (6U CompactPCI), and PMC-RTV21 (PMC module), supporting four-way parallel analog video digitization and expandable to 16 channels. It also integrates GPIO triggering, software triggering, and hardware watchdog, providing a one-stop solution for harsh industrial monitoring and visual inspection scenarios. This article will provide engineers with a detailed technical reference manual from dimensions such as model selection, hardware specifications, scalability, software drivers, API programming, and system debugging.
Series Overview and Selection Positioning
The RTV series is based on a high-performance video decoding chip (Bt878), and all models support simultaneous capture of four channel composite videos. It is compatible with color (NTSC-M, NTSC Japan, PAL-B/D/G/H/I/M/N, SECAM) and black and white (CCIR, EIA) formats, with a maximum frame rate of 30fps (NTSC)/25fps (PAL) per channel. The positioning of different models is as follows:
PCIe-RTV24/PCI-RTV24: Standard half length PCI/PCIe card, suitable for ordinary industrial computers, supports expanding the number of channels from 4 to 16 through RTV-E4 expansion board (note that the frame rate per channel is reduced to about 3.5fps after expansion).
CRTV-24 (3U cPCI) and cRTV-44 (6U cPCI): CompactPCI form, suitable for high reliability, hot swappable requirements of telecommunications or military grade systems, where cRTV-44 is a 6U size with the same expansion capability as cRTV-24.
PMC-RTV21/PMC-RTV21G: PMC (PCI Mezzanine Card) module, designed specifically for embedded or cPCI carrier boards, providing 4 video inputs and 1 GPIO, suitable for space constrained mobile or in vehicle systems.
Selection suggestion:
Standard desktop or server environment → PCIe-RTV24 (priority) or PCI-RTV24;
CPCI chassis requiring high reliability and hot swappable → cRTV-24 (3U) or cRTV-44 (6U);
Embedded or onboard integration → PMC-RTV21 (DB-9 interface) or PMC-RTV21G (10 pin pin header interface).
Core video capture specifications and performance benchmarks
2.1 Collection speed and resolution
Each channel is independently collected, and the total frame rate is accumulated when four channels are parallel. Taking the PCI-33 platform (Pentium 4 2.4GHz) as an example:
4CIF (640 × 480) RGB16 mode: All four channels can achieve 30fps real-time acquisition, and the CPU utilization rate has increased from 27% for a single channel to 61% for four channels (PCI-33 platform). If RGB24 format is used, frame loss (marked as "X") occurs when using four channels.
CIF (320 × 240) RGB16 mode: Eight channels (requiring two cards) can still be fully real-time, with a frame rate of 30fps and a CPU usage rate of 28% to 36%.
QCIF (160 × 120): 16 channels real-time pressure free, with extremely low CPU usage (<15%).
The PCI-X platform (66MHz bus) has higher bandwidth and better performance. The PCI Express platform further releases bandwidth bottlenecks. Users need to evaluate the system load based on the actual number of channels and resolution, referring to the benchmark table in the manual.
2.2 Image Processing and Scaling
Resolution selection: Supports FULL (640 × 480 NTSC/768 × 576 PAL), CIF (320 × 240/384 × 288), QCIF (160 × 120/192 × 144), and can also customize the cropping area and scaling ratio (up to 1:16) through the AngeloRTV_Set_image_Geometric function.
Color Format: Supports multiple output formats such as RGB16, RGB24, RGB32, RGB15, Grayscale (Y8), YUV, etc., to meet the input requirements of different visual algorithm libraries.
Image adjustment: It can independently adjust brightness (0-255), contrast, color tone (NTSC), color saturation (U/V component, 0-255), and has automatic chromaticity gain control.
2.3 Channel Expansion Mechanism (RTV-E4)
Three 10 pin expansion interfaces (CN2, CN3, CN5) are installed on the board, each connected to an RTV-E4 expansion board via a 10 core flat cable. Each expansion board adds 4 BNC inputs. When all expansion interfaces are used, the total number of channels in the system reaches 4+3 × 4=16. Due to multi-channel reuse of the same PCI bus bandwidth, the frame rate per channel after expansion is reduced to approximately 3.5fps (PAL) or 4fps (NTSC), making it suitable for monitoring scenarios involving non high speed moving targets.
GPIO、 Trigger and watchdog function
3.1 General I/O and Trigger
RTV-24/cRTV-44 both provide TTL compatible I/O cables, including:
4-channel digital input (IN0~IN3): can be used for external sensor triggered acquisition or alarm signal detection.
4-channel digital output (OUT0~OUT3): can control external indicator lights or relays.