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FIX incorrect calculation of payload bytes

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This commit is contained in:
Arne Hoch 2023-07-11 13:47:44 +02:00
parent ae6a93c963
commit b884081eff
1 changed files with 3 additions and 3 deletions
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6
nanomodbus.c
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@ -755,7 +755,7 @@ static nmbs_error handle_read_discrete(nmbs_t* nmbs,
}
if (!nmbs->msg.broadcast) {
uint8_t discrete_bytes = (quantity / 8) + 1;
uint8_t discrete_bytes = (quantity + 7) / 8;
put_res_header(nmbs, 1 + discrete_bytes);
put_1(nmbs, discrete_bytes);
@ -1019,7 +1019,7 @@ static nmbs_error handle_write_multiple_coils(nmbs_t* nmbs) {
if (coils_bytes == 0)
return send_exception_msg(nmbs, NMBS_EXCEPTION_ILLEGAL_DATA_VALUE);
if ((quantity / 8) + 1 != coils_bytes)
if ((quantity + 7) / 8 != coils_bytes)
return send_exception_msg(nmbs, NMBS_EXCEPTION_ILLEGAL_DATA_VALUE);
if (nmbs->callbacks.write_multiple_coils) {
@ -1577,7 +1577,7 @@ nmbs_error nmbs_write_multiple_coils(nmbs_t* nmbs, uint16_t address, uint16_t qu
if ((uint32_t) address + (uint32_t) quantity > ((uint32_t) 0xFFFF) + 1)
return NMBS_ERROR_INVALID_ARGUMENT;
uint8_t coils_bytes = (quantity / 8) + 1;
uint8_t coils_bytes = (quantity + 7) / 8;
msg_state_req(nmbs, 15);
put_req_header(nmbs, 5 + coils_bytes);