pro isubj pro jobj [PRO j signa extemplo canere] ac [PROj tela ob moenia offerre] imperatj.
signal-N-PL-ACC right away sing-INFIN and weapon-N-PL-ACC against wall-N-PL-ACC carry against-INFIN order-3-S
He orders [them] to sound the signals and hurl the weapons against the walls right away.