About CSS TM2000B
- a GPS CSS PTP grandmaster

CSS TM2000B from TimeMachines is a compact GPS-disciplined network time server: It receives the GPS time signal via the included antenna and serves it to your network as a CSS PTP grandmaster - with no internet connection required.

CSS offer it as an accessory for the CSS CANsub: When several CSS CANsub devices stream CAN data on one network, their clocks drift apart over time. With the CSS TM2000B on the network, each CSS CANsub automatically syncs to it - so frame timestamps across all devices share one absolute time base within 10 µs.

PTP in practice - 8 x CAN on LAN

In CSS CAN via Ethernet article, we deploy 2 x CSS CANsub.4 (8 x CAN) on an office switch and run a python-can test lab simulation. Without PTP, the two device clocks drift apart - eventually failing the cross-device timing checks in the test dashboard.

Enabling PTP against a software master on a Linux PC brings the devices to within 10 µs. With CSS TM2000B as hardware grandmaster, the sync is even tighter - and every timestamp is now tied to absolute GPS time rather than the PC clock.

As a second visualization, a CSS CANmod.input feeds the same signal to both CSS CANsub.4 devices. In CSS SavvyCAN, the plots from the two devices align perfectly once PTP is enabled.