koyodza (02.02.2012 12:52, просмотров: 237) ответил Скрипач на Это ваши "пожелания" или стандарт? Если стандарт, дайте пожалуйста ссылку на pdf и номер страницы.
я думал, Вы лучше знакомы со стандартом открываем Modicon Modbus Protocol Reference Guide
PI–MBUS–300 Rev. J
стр.19: Address 0 is used for the broadcast address, which all slave devices recognize
стр.33: 01 Read Coil Status. Broadcast is not supported
стр.35: 02 Read Input Status. Broadcast is not supported
стр.37: 03 Read Holding Registers. Broadcast is not supported
стр.39: 04 Read Input Registers. Broadcast is not supported
стр.41: 05 Force Single Coil. When broadcast, the function forces the same coil reference in all attached slaves.
стр.43: 06 Preset Single Register. When broadcast, the function forces the same coil reference in all attached slaves.
стр.53: 15 (0F Hex) Force Multiple Coils. When broadcast, the function forces the same coil reference in all attached slaves.
и ещё много таких же мест.
Самое главное на стр.13:
The master can address individual slaves, or can initiate a broadcast message to all slaves. Slaves return a message (called a ‘response’) to queries that are addressed to them individually. Responses are not returned to broadcast queries from the master.