This　paper　shows　a　sampled-data　consensus　design　for　heterogeneous　linear　time-invariant　(LTI)　multi-agent　systems.　To　achieve　the　ripple-free　design　requirement　and　to　provide　estimates　of　the　locally　maximum　allowable　sampling　periods　(LMASPs)　for　the　problem,　we　develop　an　internal　model　principle　approach.　The　present　study　extends　the　continuous-time　cooperative　robust　output　regulation　(CROR)　investigations　in　literature　and　offers　a　ripple-free　solution　with　estimates　of　the　LMASPs　by　means　of　monodromy　matrix-based　stability　analysis　for　hybrid　systems.　We　also　present　a　numerical　example　and　perform　simulations　using　Hybrid　Equations　(HyEQ)　Toolbox　in　literature　to　illustrate　the　proposed　results.　©　2020　Technical　Committee　on　Control　Theory,　Chinese　Association　of　Automation.