6100 BSC Programming Manual

Writing Applications that Use 6100 BSC
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| |
| Local Station Remote Station |
| |
| a) / | READ request |
| READ | EOT ---------> | (completes with |
| request | / status 163--EOT) |
| | \ |
| (turns | <--------- ENQ | WRITE |
| line | | request |
| around, | ACK 0 -------> | (makes bid, sends |
| accepts | | first message) |
| bid) \ <--------- msg | |
| / | |
| READ | ACK 1 -------> | |
| request | / |
| |
| |
| b) / |
| READ | EOT ---------> |
| request | |
| (completes | (no reply) |
| with status | |
| 171--no reply) | |
| \ |
| / |
| WRITE | ENQ ---------> \ |
| request | | READ |
| (makes bid) | <--------- ACK 0 | request |
| | | |
| | msg ---------> / |
| |
| |
| c) / | READ request |
| READ | EOT ---------> | (completes with |
| request | / status 163--EOT) |
| (completes | \ |
| with status | <--------- EOT | CONTROL EOT |
| 167--EOT) \ | (declines to bid) |
| / / |
| WRITE | ENQ ---------> \ |
| request | | READ |
| |
| |
| The underscore shows the information applications |
| supply and receive. In each case, the information |
| resides in the text field of the request/response |
| buffer (see Figure 3-9). Items not underscored--for |
| example, most control sequences--are supplied and |
| received by the protocol, not by the application. |
| |
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Figure 3-8. Relinquishing the Line (Options)
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