I'm a rank beginner in using OpenModelica. I've made a mechanics.translational model (called sls_m) with 2 springs, a damper, a fixation and a force,  and successfully simulated with a step force and with a sawtooth using blocks.sources.sawtooth. I've also successfully used blocks.sources.trapezoid with its default parameters (which create a square wave). However, when I start trying to turn it into a triangular wave by setting any of its parameters, I get the message 'Error: Variable rising not found in scope sls_m'. Can someone please tell me how I'm supposed to set these parameters, or where it's documented? Thanks. - Robert