CV630-IP RS-232 Command Set
www.marshall-usa.com31 32
Pic. 1 Packet structure
Note:
Pic. 1 shows the packet structure, while Pic.2 shows the actual waveform. Data
flow will take place with the LSB first.
Pic. 2 Actual waveform for 1 byte
17. Communication method of VISCA over IP
17.1 Communication method
VISCA over IP can process the VISCA communication between the controllers and
peripheral devices using the messages that can be identified on the LAN, and sends/
receives them. Because of this, VISCA over IP is not concerned about the contents
of the communication between the controllers and peripheral devices. However, the
VISCA communication sequence is different, depending on the types, as follows.
RS232/RS422 connection IP communication connection
While the IP communication connection, the address of each device cannot
be set in the RS232 message as it is because the controllers and peripheral
devices that are connected simultaneously are increased. In this case,
addresses of the controllers and peripheral devices that are set in the RS232
message are locked to 0 (for the controller) or 1 (for the peripheral device).
16.9 Packet Structure
The basic unit of VISCA communication is called a packet [Pic.1]. The first byte
of the packet is called the header and comprises the sender’s and receiver’s
addresses. For example, the header of the packet sent to the SRG assigned
address 1 from the controller (address 0) is 81h in hexadecimal. The packet sent
to the SRG assigned address 2 is 82h. In the command list, as the header is 8X,
input the address of the SRG to X. The header of the reply packet from the SRG
assigned address 1 is 90h. The packet from the SRG assigned address 2 is A0h.
Some of the setting commands for SRG can be sent to all devices at one time
(broadcast)*. In the case of broadcast, the header should be 88h in hexadecimal.
When the terminator is FFh, it signifies the end of the packet.
*The broadcast function is not available for VISCA over IP.
To Next Page
Loading...
