When you work with a ZTE modem and want to receive and SMS and the delivery Reports you face a specific problem.
Have ZTE modems, all incoming SMS are stored in memory SM, and reports are stored in the memory of SR
memory modems. As modems got memory ME, MT.
AT+CMGD method only works for SM, ME, MT. SR only works for CPMS.




To receive the reports for FREE you need to go through the memory of the SR method with CPMS. But the fact that +CPMS: "SM",0,20,"SR",0,100,"ME",0,100 in reality look like
SM has indexes 0-19
ME has indexes 0-49
SR has indexes 50-99

If you set



When memory_start = 50 will not be able to read incoming SMS.
When memory_start = 0 delivery reports are checked for too long (about 6-8 seconds is too much non-existent cells).


Offer variant:
1)


2)


3)

I've modified the sources and introduced an additional parameter secondary_memory_start.
The final configuration for ZTE (MF628, MF100 tested)



The result is no delay and error in reading status and sending messages

I've modified smsd_cfg.h

typedef struct { ... + int second_read_memory_start; // second read memory space for sms ... }

I've modified smsd_cfg.c

void initcfg_device(int i) { ... devices[i].second_read_memory_start = -1; ... }

and included the treatment of this parameter in the smsd.c for // Dual-memory handler:
... //3858 found=0; if (used_memory>0) { if (max_memory == 0 && memories == 1) max_memory = DEVICE.secondary_memory_max; if (!value_in(DEVICE.check_memory_method, 6, CM_CMGD, CM_CMGL, CM_CMGL_DEL_LAST, CM_CMGL_CHECK, CM_CMGL_DEL_LAST_CHECK, CM_CMGL_SIMCOM)) { if(memories == 0) { sim = (DEVICE.read_memory_start == -1)? 1 : DEVICE.read_memory_start; } else { sim = (DEVICE.second_read_memory_start == -1)? 1 : DEVICE.second_read_memory_start; } } for (;;) { if (!(*delete_list)) if (terminate == 1) break; if (value_in(DEVICE.check_memory_method, 6, CM_CMGD, CM_CMGL, CM_CMGL_DEL_LAST, CM_CMGL_CHECK, CM_CMGL_DEL_LAST_CHECK, CM_CMGL_SIMCOM)) { if (!(*memory_list)) break; sim = atoi(memory_list); if ((p = strchr(memory_list, ','))) strcpyo(memory_list, p +1); else *memory_list = 0; } else { int i = (DEVICE.read_memory_start == -1)? 1 : DEVICE.read_memory_start; if(memories == 1) { i = (DEVICE.second_read_memory_start == -1)? 1 : DEVICE.second_read_memory_start; } if (sim > i + max_memory - 1) break; } ....

This is not the best option but I don't know the programming language in which is written the source code the Author can make this moment much better.