=> ACK | - if data is received correctly, or |
NAK | - if an error has occurred |
*The host sends a command to and receives a response from the terminal in one poll cycle; it then acknowledges receipt of the terminal command response:
=> | STX, CMD, parms, ... CS1, CS2, ADDR |
<= | ACK - if data is received correctly and no response is |
| required, or |
| NAK - if an error occurred or if there is response data |
| to be sent. |
<= | Command response and data: |
=> | ACK - if a command response was sent from the |
| terminal and received correctly by the host, or |
| NAK - if an error occurred in the command response |
4.4.2.Commands
The following commands are supported for download, diagnostic, and application data transfers. Each command and its parameters will be framed as shown before being transmitted; responses have the same format without the ADDR fields.
STX, CMD, parms, ... CS1, CS2, ADDR
ESC 0 - Application data |
| |
=> | STX ESC 0 | <data> CS1 CS2 ADDR |
<= | ACK or NAK |
Since the MR350MKII has only one frame to hold the single incoming application data, and the frame will not become available until the holding data is retrieved by terminal? application program. Therefore, it is important to check the terminal echo back status whether ACK or NAK to sure the terminal has received the data.